Laguna Seca: where summer meets winter (1/3)

Intro: lack of oxygen, excess of radiation

Bolivia is entirely situated in the tropical belt, but due to the huge differences in elevation has a diverse and complex climate. While the eastern part is dominated by wet lowlands and savannas, the western sector is mostly a high and dry plateau named the Altiplano. With an average elevation of around 3800 meters, this barren highland which is shared with three other South-American countries (Peru, Chile and Argentina) is the second largest and elevated in the world after the Tibetan Plateau, concomitantly the air contains only about 60% of the oxygen found at sea level.

The driest part is represented by the westernmost stretch, which gradually descends into the hyper-arid Atacama desert towards the coast of the Pacific Ocean. In Bolivia it can be found in the south-western corner of the country. In the middle of this region there is an extensive flat area covered with thick salt crust named Salar de Uyuni, which represents the closed bottom of the highland’s interior. As such, it has no outlet and all the rivers (mostly intermittent) are collected by the huge, shallow bowl where the water rapidly evaporates in the thin and dry air.

*With more than 10.000 square km surface area, Salar de Uyuni (3660 m) is the largest salt flat in the world*

The climate of the plateau is extreme. Especially notable are the daily temperature fluctuations, which can exceed 30 degrees in the dry season, which has its peak in the south hemisphere’s winter months (June-August). Beside the huge thermal amplitudes the other peculiar weather aspects are the strong westerly winds and the intense UV radiation. Regarding the latter, the highest value ever recorded on the surface of the Earth – an incredible 43.3! – was measured on the peak of Licancabur volcano (5916 m) situated right on the border between Bolivia and Chile on the fringes of the Atacama. Just imagine that the level 11 is considered “extremely high” on the UV chart and most European countries never reach that even in the summer.

Choosing the target

While already knowing that the Altiplano likely provides the best general context regarding the biggest daily temperature fluctuations, I was of course interested in the “finer details” which can maximalise this potential. Regarding the timing I concluded that the best period must be somewhere near the equinox, when the heating and cooling has similar chances of manifestation. As with both very short nights (think of polar summers) or very short daylight (think of polar winters) the thermal amplitudes are pretty small (constantly cool or constantly frigid), the biggest ones have to be equally far from both.

*The location of the research area (black dot) inside the Altiplano (gray spectrum)*

Concomitantly, much better is to have an abrupt sun-path, where the irradiance reaches the highest possible angle at zenit (namely tropical latitudes). This is of course influenced also by other factors such as the distribution of moisture (clouds and precipitation) between the seasons.

Taken all into account the month of September stood out as according to the available climatological statistics (Uyuni in Bolivia, Calama and San Pedro de Atacama in Chile) in the south-western part of the Altiplano it is the same dry as the mid-winter period, receiving almost no precipitations. Now let’s move to the topographical aspects.

*Topo-map with the unnamed depression (lower-right center) situated east of the Alota – Villamar Mallcu dirt road*

As the thinner air has less heat-retaining capacity, the general rule to follow is: the higher the better. In the simplified version the limitation is given by the highest possible elevation where closed basins can be found as in those places the colder air can be gravitationally collected. But there are also other influencing elements like the wind pattern, which instead is inversely proportional with the targeted amplitude potential, making the real picture more complex. Best should be (especially for shorter term observations like mine) to make a wise compromise, founding the “golden mean” between elevation and stability.

As such, I concluded that around 4000 meters elevation must be a well grounded decision, sufficiently high to have a serious advantage compared to the low elevations, but still relatively stable compared to the protruding tall ridges and peaks where the wind is certainly more active.

*Satellite view of the endorheic basin with the contour levels 30, 20, 10 and 5 meters* *marked with red*

Meticulously scanning the map I found out that there are only a few closed basins with sufficient depth which doesn’t have lakes on their bottom and of course exactly these are the best for my purpose. Finally I’ve chosen an unnamed depression south of Villa Alota settlement, whose floor is situated around 4030 meters, while the outflow point is some 30 meters higher. The bottom looks completely dry, lacking even the characteristic white salt crust.

Brief summary of the research

The Bolivian journey started on 13th September, landing in Santa Cruz de la Sierra, the biggest city of the country. Continuing with an internal flight to Sucre, the next day I reached an intermediate elevation between the hot lowlands and the arid high plateau. After two other days of acclimatization I arrived in Uyuni on 16th by bus via Potosí. On 17th I traveled to Villa Alota with a previously hired private jeep to begin the research as soon as possible, approaching the chosen spot a little more on the dirt track towards Villamar Mallcu. I started the hike with the equipment around 1 PM.

After around 1.5 hours I reached the bottom of the nameless endorheic basin where the instruments were mounted on the tripod, which was also stabilized with an attached bag filled with rocks. The coordinates are 21.498 S, 67.547 W, the elevation around 4030 m and the distance of the sensor from the ground is 170-180 cm. The weather station started its operation at 2:56 PM. First reading: 14.4 degrees Celsius.

I did not waited long here, but returned from Alota the next day to spend the following two nights near the equipment. In all three cases the temperature dropped below -15 degrees, the coldest being the third morning with -16.5 degrees Celsius. The sky was generally clear with some altocumulus invasions during the evening and the first part of the second night. The wind pattern has a pretty obvious course, the afternoons being dominated by strong westerlies, while the nights and mornings are much calmer. I left the research spot in the morning of 20th and spent the following days in and around Uyuni.

*The weather station on the bottom of the basin*

After six days I returned to the endorheic basin for one last night after which the equipment was collected. That morning (27th) was the coldest of the entire research (-19.0 degrees Celsius at 6:23 AM) and it was also the period when the biggest thermal excursion happened: 38.1 degrees in under 24 hours, starting the huge drop from the previous day’s positive 19.1 degrees.

Six out of ten days the temperature fluctuation exceeded 30 degrees (dropping every time below -10) with a very likely seventh (the day before the last) when the strong afternoon wind overturned the tripod disconnecting the sensor. The middle days were somewhat milder, when at times I observed partly covered sky in the Uyuni area.

*The coldest morning of the research was the last one*

During my solitary hikes I saw many llamas on the outer slopes of the basin, where the locals have started the spring work on the quinoa fields and only vinunas inside, on the bottom. I spotted also some eagles, a viscacha and observed Darwin’s rhea (suri) tracks in the sand. Near my camp which was situated a little higher on the northern slope I identified signs of smaller scale mining activity. Except the relatively busy dirt track where the tourist filled 4wd cars circulated the surroundings lacked human presence, meeting only once two llama herders on the periphery of the basin.

The instruments used in the field

-One LogTag UTRED30-16 data logger with the measuring range between -40 and +99 degrees Celsius, an accuracy of 0.5 degrees Celsius and a resolution of 0.1 degrees Celsius

-One Greisinger G1710 thermometer with the measuring range between -70 and +250 degrees Celsius, an accuracy and resolution of 0.1 degrees, used for instant hand measurements

-One photo camera tripod serving as the support for the instruments

-One helical solar radiation shield from Barani Design Technologies: https://www.baranidesign.com/

*The Barani Pro shield fighting against the vicious UV radiation*

To be continued…

Laguna Seca: where summer meets winter (2/3)

Journey photo album

Catedral Metropolitana Basílica de San Lorenzo, Santa Cruz de la Sierra: My plane landed at Viru-Viru airport on 13th September where hot wind (around 36 C) and haze greeted me. Feels also pretty humid. Not the weather I came for, but certainly an interesting debut.

The city has a rapid pace, maybe too rapid for my taste. You must be careful with the traffic, the drivers does not have much patience here. At the central square is better. During the night the weather changed, cooling down significantly (around 20 C) because of the torrential rain. Only the wind remained there from the old equation. Back to Viru-Viru, as I have local flight to Sucre.

Big festivity in Sucre: With some delay the plane landed at Alcantari aiport (3100 m elevation), around 30 km from the city (2800 m). Taxis are not expensive here. While Santa Cruz (400 m elevation) has some dodgy neighborhoods and can be challenging during the night (I didn’t tried out), Sucre feels much more safe and is also cleaner. Let’s forget about the mess after the mega-party, it was rapidly cleaned the next morning. *Not my head which was heavily strucked by “soroche” (altitude sickness) because of the rapid change from near sea-level. It was kind of surprising, never felt ill at this elevation until now.*

At “Jesus’s heart” monument the next day: Around noon my condition improved, so went out to do some mild cardio workout. This hilltop (300 meter elevation gain) was a good choice to check the gears. The communal cohesion is evident in the city, which is known as the second capital of Bolivia. Locals may say it’s the real one.

*Also known as “the white city”, with its general colonial aspect, Sucre has a positive and tranquil vibe*

Yes, those are palm trees at 2800 meters. The climate here is one of the best in the country, which can be summarized as a constant spring. Not hot, not cold, not too rainy, not too arid. But don’t underestimate the UV radiation, which isn’t modest.

Potosí historical center: Reaching the heights of the Altiplano (almost 4000 meters) the next evening by bus, I felt in my elements both physically and emotionally. The soroche didn’t returned. I’ve read before that the body’s reaction to the high elevations are pretty unpredictable, now I experienced it live again.

Similar in its colonial aspect with Sucre, Potosí is dominated by pastel colors (especially pinkish), which gives him a more ancient general look. While Sucre can be considered the heart of national identity, here is the center of the spanish heritage. *Pleasant cool morning, around positive 5 degrees between the old walls.*

*Statue of liberty: nice hyperboloid shape by the way*

*Yeah, definitely has a soul, I think it’s my favorite bolivian city*

View from a tower towards Cerro Rico (4780 m), the famous mountain which had the biggest silver mines in the world in the 16-18. centuries, strongly contributing to the rapid ascent in power of the Spanish Empire. Still a lot of inner richness there in our days. Well, take this literally, *the actual story behind the exploitation is less appealing from a humanistic perspective.*

Villa Alota: After another 4 hour bus journey to Uyuni, only slept there once as I felt rushed by the good weather conditions to start the research as soon as possible. Having a previous arrangement in this regard to hire a private jeep, we reached the very basic looking settlement on the new paved road before noon. It was windy as it can be, what a start!

Flamingoes in the wetlands (bofedales): I decided to stay 3 days in the area, spending the latter 2 in the wilderness, while in this first one I will sleep in Alota after placing the measuring equipment. *The forecast shows the best conditions for the second and third night, that’s why.*

Henry, the driver with a lonely altocumulus lenticularis above: Continuing on the dirt track in the direction of Villamar Mallcu around 15 km, we approached the chosen place more and before 1 PM I started the hike

*Above 4000 meters elevation:* O yeah, I was waiting for this from a long time. Too bad, my GPS died right at the starting spot (could be the dust or just bad timing?) Anyhow I have everything crucial in my memory, let’s get into it.

First view of the endorheic basin: It seems that I guessed the directions right, the edge of the depression wasn’t too far. The weather is still windy, though less than in Alota where was on the border of violent. The temperature is moderate. *Unsurprisingly, nobody in the entire area*.

Reaching the bottom around 2:30 PM, I mounted the instruments on the tripod, secured it with an attached bag (actually the tripod’s own) filled with rocks collected near the slope and shortly before 3 PM the logger was started: 14.4 degrees Celsius, must be around the hottest time of the day. The wind persisted.

*First milestone, happy with the installation*

*Even flatter than I thought, the bottom of the basin is situated around 4028 m according to Google Earth*. *The vegetation is made up mostly by separate patches of Paja Brava (Festuca orthophylla), which often grow in this characteristic circle arc format.*

*Must have been vicuñas (wild relatives of the llamas), I saw a few running in the distance in the eastern part of the basin*. *Planning to reach Alota before dark, I left the research area already before 4 PM. Isn’t really a must, but I’m a guest in the village and not sure about the quechua ethics regarding the dinner*.

The track I follow on the way to the village is flanked by quinoa fields. Beside the llama meat this plant is the other basic food of the local population, between the very few which can grow at these elevations. *It seems that the spring work (sowing) has already started in some parts.*

*Trying to do a shortcut as the road turned too much to the left, around sunset I reached the wetland situated south of the village*

*Beside the flamingoes this is a very common bird species here. Sometimes they will fly round just a few meters above your head, while screaming. Not a welcome sign, I guess.*

*Altocumulus lenticularis is by far the most common cloud type here. Must be very windy at the highest elevations.*

It seems that I will not make it to the village during daylight. The marshland’s topography forced me to turn to the left myself too, like I was corrected by an invisible quechua policeman because I did not follow the local rules. No bad feelings, I really like the ambiance here. More adventure, the better.

*The cool evening wind is an early precursor of the cold night what will follow it*. *I reached Alota shortly before 8 PM after an almost 20 km hike, much more than the direct line which shows only 12 km*.

Early morning in the remote village, the sky is clear, the wind has gone

*Far from the previous day’s sunny afternoon*

*You can buy coca leaves here (legal in Bolivia), a mild to medium (if you chew as much as a cow) stimulant, frequently consumed by the locals*. *Be sure your mouth will feel numb as after a visit to the dentist.*

*The small green bag on the big one: As you can see I’m prepared for the long hike, three sunny days (read it as UV blast) and two cold nights are waiting for me*

The weather warms up quickly and the first daylight hours are basically windless. This seems to be a general pattern here, which often extends to around noon, the wind starting to increase only in the early afternoon.

*The wetland has a rich and variate fauna even in the dry season, beside the bird species there are many llamas, sheep and even bovines*

*As I heard they leave the area only in the winter months (June-august), so possibly returned here not long before*

*First I want to visit a canyon area, which is situated a few km’s to the east from my main target*

*The warming continues, without wind the temperature differences are very noticeable*

*Reaching higher elevations, I continue the hike on rougher terrain*

The top part is very fragmented, thus after meandering my way through the rock-labyrinth for some time I concluded it’s a bad idea to continue, trying to go round all these ravines and decided to return before heading to the endorheic basin. I have a heavy backpack with limited water for a big and more strenuous bypass. Let’s be reasonable.

*Noon approaches.* *One can almost sense the UV burn just looking to this picture*.

*Extensive quinoa fields on the other side, a reminder that this barren place is not entirely forgotten. Jubina mountain is in the right side of the background, that’s my direction*.

*The water in the stream is surprisingly balmy. I suppose it’s a hot spring area, I don’t think the daily warming itself could do this.* *However, careful with the drinking, many llamas are present in the surroundings. I mean DON’T.*

*Crossing the terrain transversely is not that straightforward even is there are no topographical obstacles of major scale*

*I see now, that’s actually the main canyon, the more visited one. I was in a secondary one, though likely the same spectacular.* *Maybe I miss the GPS a little.*

Crossing the shallow river. If not before, now I am using the “legionary hat” as my face started to feel the abrasion caused by the intense radiation. And not only the face. The exposed parts of the skin (which are pretty large as I am wearing shorts and T-shirt) are continuously attacked from various directions. Doing a lot of outdoor activities in all seasons from many years, I think that never felt burning sensation on my arms and calves before since childhood. *But you can’t really prepare to this level of UV intensity (13-14 now), it’s clearly above the European scale.*

Another small scale ravine on the other side. Look, a viscacha! Oh, it’s gone, had no time to record it. Very quick, likeable creatures, with their appearance somewhere between a rabbit and a squirrel.

*The campesinos (local farmers) working on the quinoa fields. Well, even if they live here from centuries, are fully clothed and are using hats…*

A little later I reached the dirt road where the 4wd cars circulate towards Laguna Colorada and the Siloli desert. Jesus’s heart was present and I received a full bottle of water (did not asked for) from a kind female tourist after stopping to curiously ask what the heck am I doing here alone with a heavy backpack. Now I’m sure I will stay both nights outside.

Reaching the col of the basin. The slightly undulating terrain was misleading as there were more topographical discontinuities than one could conclude simply looking from the distance. A little tired until now, the elevation taxes you and it’s different with a bigger luggage.

On the cracked bottom of Laguna Seca, which locals told me is the name of the place studied by me. Proper name.

WHAAAT !? *This was one of the biggest and most pleasant surprises of all my cold-hunter career* *until now*. *NINE degrees below Alota, which itself is already on the bottom of a flat basin? This is the definition of a Jackpot. And the following two nights could even beat that!* *How about the 33.3 degree amplitude?*

*Yeah, some vivid colors there. Maybe I too should have used Mr. Barani’s helical radiation shield?*

After scanning the surroundings I decided to spend the night a little higher on the southern slopes of Jubina mountain. Spotted there a rudimentary building, which later identified as related to a nearby small-scale mining activity. Shortly after I changed my mind seeing a lot of rodent feces in one corner inside the rectangular walls. I like animals but don’t want to wake up with jerry on my face…

*More exposed to the elements, but another level of freedom. Good night! Wait, it’s only around 5 PM* or so.

*Park ranger feeling. Not the best payment, but nice view.*

Was the night good? To be honest, far from my favorite one. Despite the optimistic forecast regarding a completely clear sky, from the late afternoon well into the second part of the night there were constant altocumulus invasions like the place was seriously cursed. And the previous one – which I decided not to spend here – was spotless, despite the forecast showed partial cover. The westerly clouds are just coming and going, but never disappearing completely. I fell asleep late, but when woke up around 4:30 AM the sky was clear and there was barely any air movement. Great! My thermometer showed -3 degrees, must be a strong inversion down there. Soon I was ready to an early morning visit to the weather installation.

Indeed, in the lowest part of the basin it suddenly felt colder. The air was completely still. I guessed well, the minimum is well below -10, but less cold than the previous morning. Not bad after the altocumulus marathon.

*No T-shirt time anymore, the lack of rest also weathered me a little*

*Sunrise above Cerro Tomasamil (5890 m), the highest peak you can see from my research spot* *(around 50 km as the bird flies)*

*That likely was a vicuña, but what killed it? A cougar (puma) could be part of the equation, no doubt*

*Around 8 AM already reaching the positive range, that’s a serious leap!*

This is what I talked about a little earlier: there are a few crevices in the rock nearby, which evidently are anthropic. Then I remembered the conversation with the quechua woman in Alota regarding Jubina mountain: “it’s very rich, silver, gold and many other”. Maybe they think I am a gold-digger in disguise?

*Until the early afternoon he weather warmed even above yesterday’s maximum. You can’t really comprehend it’s the same day on the same spot.*

*Maybe only the pretzel shaped tufts of paja brava know what this remote basin’s climate is capable of*

The second night was completely clear, though somewhat windier in the evening. As at dawn the mobile thermometer showed -5 degrees at my camp, I knew it will be even colder on the bottom this time. And it was: -16.5 degrees, the lowest temperature until now.

*The golden mantle lowering into the depression*

*I left the research spot in the morning and hiked back the roughly 20 km’s to Alota. This must be the dwelling-place of a llama herder, but nobody at home now.*

*The vicuñas are the ancestors of the alpacas, also related to the llamas. Very common on the Altiplano, you can spot them often near the road while passing by car.*

Hitchhiking around noon in UV-strucked Alota. A few years ago the road was paved, so now it’s pretty easy to reach Uyuni with basically any means of transport. I was lucky that the Calama bus (from Chile) passed there less than 30 minutes after my arrival and of course the fare was very cheap.

*Train graveyard in Uyuni*: *Until the late 19. century the silver mining in Potosí declined thus the carriages transporting the mineral to the Pacific coast through the Atacama were left pray to the time and elements.*

In the evening of the return I observed signs of a respiratory infection which intensified the next day (likely flu), so I decided to take some rest. Regarding the original plan this meant a single important change: there will be no climbing. Hard to accept it, but that was the proper rational decision. I have to return to collect the equipment in less than a week, so I will not play the Russian roulette. That’s it, next time. *I still went out to visit the train wreck at the periphery of the town. Interesting*, but…

…*too bad for the garbage field you have to cross from and to the settlement* *if you come by foot*

My condition didn’t improved – to say the least – so stayed mostly inside the following day, but afterwards I felt somewhat better and went out to a walk again. This time the purpose was to identify the weather station, which I concluded it must be somewhere in the area of the airport (some 5 km from the center). I want to visit it and, if possible, obtain some data to compare it with my measurements. As I couldn’t see it from the road and did not know the local rules regarding the airport security (saw soldiers patrolling inside the fence), decided to return and ask the hotel staff regarding this.

Feeling stronger it was time for a longer trip. I visited the Salar de Uyuni, one (more correctly THE) of the country’s main attractions. At 3660 m elevation, the extensive saltpan is the worlds largest measuring over 10.000 square km and almost 150 km across. You heard it right.

As in case of many other scenic places, tourists arrive here through organized group tours (one or more days) by jeep. However, for eccentrics like me is more palatable to do this “freestyle”, so I reached Colchani village by bus (less than US $1) and continued by foot. From the asphalt it’s 4-5 km to the edge of the salar. Under the spell of the infiniteness I could not resist and just walked and walked forward. After a while I saw something in the distance, of which first wasn’t sure if are cars (there is also some exploitation near the shore) or some flatter buildings, but later turned out to be the latter. It was a complex built in and from salt. For tourists of course.

*Does it look a little like Antarctica maybe?* *Be sure, it’s only the look as the UV radiation is at a different level here.*

*The place is named “Dakar Monument”* *and concluding from the walking time must be around 8-9 km inside the salar*

*On the way back. Convective clouds are evolving above the eastern ranges (towards Potosí)*. The hike was technically easy (very flat) but pretty long (26-28 km) for a “warm-up” after the flu. However, the distance per se should have not be an issue. The problem was the notorious radiation, more specifically the reflected one. I read that a sunglass is a must here, but as I didn’t felt anything suspicious regarding the vision while hiking, just continued without protection. Bad decision. The inflammation started only in the evening and wasn’t over the next day. How can I describe the sensation? Well, imagine that your eyelashes became your worst enemy. *You can’t close them because they will feel like wires scratching the surface of your eyes. So, good night…*

On the third day following the UV incident my vision improved sufficiently to can safely return to collect the equipment. It was also the planned date to do this. After some less potent days, the forecast shows a new cooling in progress, so I was optimistic regarding this last night which I will spend in the wilderness. Taking the Calama bus at dawn, started the hike from Alota in the morning. It was pretty chilly, definitely below -5 degrees. This time I continued to stay on the main road more, turning left towards Jubina only after about 12 km’s. Reaching the periphery of the closed basin I observed two people so entered in conversation and found out they are herders searching for some missing llamas. Told them I only saw vicuñas inside the basin.

Reaching the bottom I tried to identify the tripod as soon as possible, but as I approached it became clearer and clearer that something is wrong. The suspense was over after finding the structure in its place, though overturned. So: wind, animal or human? Turned out to be the first as both the falling direction (towards east) and the time of the incident, which I concluded later from the interrupted graph (between 3-4 PM) supported this theory. As the weight-reinforced installation felt pretty stable and easily bearing the first days wind, those gusts must have been wild.

*Around noon the radiation was over the scale again, hard to found a shelter in this period as the sun is very high on the sky*

*Feeling well, decided to do a hike to the top of Jubina*

*Queñoa* *(don’t mistake it for quinoa), the highest living tree in the world has an easily exfoliating surface*

*The other endemic plant of the highest elevations is the Yareta (the moss looking one), which often lives in a symbiotic relationship with the former*. *But don’t be fooled of the aspect, it’s hard as a rock.*

*Wind and UV: On top of Jubina (around 4400 m)*. *I wouldn’t consider it a “true climb” – in the bigger context it’s more like a hill here – but it was the highest point I reached during the journey.* *RIP Garmin watch, I lost you here.*..

*Maybe my favorite plant? Definitely special.*

*The thick foliage of the queñoa evolved to can endure the drought and the strong wind of the barren plateau*

*Uturuncu (6008 m) the highest mountain in southern Bolivia and the salt flats of Laguna Yapi (4000 m). The whitish top of the mountain is not snow, but volcanic debris*

*Zooming the bottom of Laguna Seca. Yes, I can spot the weather installation*.

*Descending the rocky slopes*. *The return to the camp was straightforward and also much faster then the wandering on the bumps of the plateau*

*Last morning temperature check: The evening and night was completely clear and also the calmest of all*, *thus* *the temperature plummeted extremely low, reaching -19 degrees just before sunrise.* *What a finish!*

*The endorheic basin exceeded my expectation*

*The research is over, the results are excellent*

*Darwin’s rhea (Suri) tracks in the sand near the basin’s col*

*The hike back to Alota was the same long (if not longer) as this time continuously followed the trails between the quinoa fields, without trying to do shortcuts*

*Guardians of Uyuni*. *After hitchhiking for a while, a truck coming from Chile took me back to the town, same cheap as the bus.*

*Everything is revolving around tourism in Uyuni, the small town is full of agencies, accommodations, souvenir shops and small restaurants*. But of course, I was more interested to get in touch with the weather station. The problem was resolved with the helpfulness of the hotel staff who arranged a meeting with the weather personnel of the airport. The data I obtained there is valuable (see the third chapter)

*A lost sherpa?* *The descendants of the incas might be of smaller stature but they’re far from weak*

*Nothing more bolivian than this colorful load-pack*

*It was time to start the return. Following the same way by bus, first I reached Potosí*

*The well decorated “church of indians”, unfortunately not open for visitors*

*The top of San Francisco church overlapping with the pyramidal peak of Cerro Rico* *(author’s fault)*

*Now the “Casa National de la Moneda” was open and I take the opportunity to visit it in the last hours of my stay*. *It’s Sunday and pretty crowded because of the short program, but worth the patience.*

“Triangular virgin”, a mix between the new Christian religion and the older native mountain veneration

*Some old coins from the early minting style (16-17th century)*

*Inside the chamber with the huge gears which operated the mint*

*Pieces of art made from the abounding local silver*

*The next day I continued the bus trip to Sucre*

*Despite the poor statistics in comparison to other South-American countries, Bolivia’s “second capital” radiates a general feeling of prosperity* *and proudness*

*From Sucre I descended to the savanna climate of Santa Cruz with the 45 minute local flight. The same journey would take 11 hours by bus and the cheap prices support the good decision.* *Again hot and windy. And dusty.*

*He just stood up and elegantly walked like this for a while, before changing into tree-acrobatics mode*

*Nandu. A smaller relative lives also in the Altiplano (remember the tracks in the sand?)*

*Well, I think we’re not completely done here. Hasta luego, amigos!*

to be continued…

Laguna Seca: where summer meets winter (3/3)

Interpretation of the logger’s graph (using LogTag Analyzer 3 software)

*The temperature curve of the 10 days/ 10 nights research period. The device was registering a value every 2 minutes.*

First day and night (17-18th September)

I installed the measuring equipment on the bottom of the endorheic basin in the early afternoon during moderately windy conditions and almost clear sky. The logger set for 2 minute intervals was started at 2:56 PM and the first reading showed 14.4 degrees Celsius. Concluding from both the time of the day and the temperature curve it was around the hottest part of the day, reaching the slightly higher maximum of 14.7 degrees at 3:25 PM. I left the equipment before 4 PM and hiked back to Alota under generally clear sky with some altocumulus lenticularis clouds over the higher mountains. The moderate wind persisted also in the evening.

*The temperature curve of the first afternoon and the following night*

After a smoother afternoon start the temperature drop is slightly disturbed in the evening and night but generally is pretty straightforward. Descending below 0 for first time at 10:35 PM, the continuous negative values started right around midnight. The minimum of -16.2 C was reached at 5:11 AM and was approached again with -16.1 C at 6:25 AM before sunrise. I spent that night in Alota and measured -7 degrees outside in the early morning during clear and calm conditions.

Second day and night (18-19th September)

After sunrise the temperature rise is fast and clean, already passing over 0 degrees around 8 AM. Later the curve becomes less and less abrupt but has a general constancy until around 3 PM, reaching the peak of 17.1 C at 3:49 PM. Together with the -16.2 C morning minimum this means a 33.3 degree temperature excursion in the same day. The obvious drop starts around 4:30 PM becoming more pronounced after 5:20 PM. Like in the previous night’s case, the afternoon drop is the cleanest while the evening and first part of the night somewhat disturbed, still without significant changes on the higher scale. The 0 degree mark was passed for the first time at 11:21 PM, while the continuous negative values started from 0:45 AM. The minimum of -15.2 C was reached at 6:17 AM.

*The temperature curve of the second day and the following night*

I spent the night in the basin at my camp situated a little higher, outside the inversion layer on the southern slope of Jubina mountain. Despite the optimistic clear forecast, from the late afternoon well into the night there were constant altocumulus (also cirrostratus) invasions, passing from west to east and partially covering the sky between 1/8 and 5/8 ratio. The wind was generally weak, reaching the lowest speed at dawn when the sky finally became completely clear. I was present at the research spot during the coldest period before sunrise and observed calm conditions on the bottom.

Third day and night (19-20th September)

I continued to stay in the basin observing an all day long clear sky. The very rapid temperature rise passed again above 0 degrees around 8 AM, the curve becoming less abrupt before 9 AM. This time the maximum of 17.8 C was reached a little sooner at 2:15 PM, which together with the -15.2 C morning minimum represents a 33.0 degree daily amplitude. The warmest early afternoon period is characterized by pretty big 1.5-2 degrees small scale oscillations in short periods of time. The general drop started after 4 PM and again the cleanest part was the late afternoon. The evening and especially the night was less stable, where a 5 degree warming happened around 2 AM and only after that started to drop rapidly again. It reached below 0 for the first time at 11:17 PM, while the continuous negative temperatures started from 0:35 AM. The minimum of -16.5 degrees Celsius was reached at 6:03 AM, thus slightly exceeding the first nights low.

*The temperature curve of the third day and the following night*

I was present in the area, spending the night at my camp and checking the logger in the coldest early morning period. During the dark hours I observed no clouds at all and only weak, sometimes moderate wind on the slope. Regarding the earlier mentioned abrupt night warming, as I can’t recall any clouds on this night, the disturbance was likely caused by wind alone. On the bottom was calm again at dawn and morning.

Fourth day and night (20-21th September)

I left the research area after sunrise and hiked back to Alota from where traveled to Uyuni by bus. In Alota was still completely clear and close to calm around midday. The diagram shows the characteristic undisturbed morning warming, passing the 0 degree mark again around 8 AM and continuing the rapid increase above 6 degrees Celsius at 8:50 AM. With a more moderate but still generally constant ascending slope, the peak of 18.4 degrees was reached at 3:09 PM, which together with the morning’s -16.5 C represents an impressive 34.9 degree daily amplitude, the biggest until now.

*The temperature curve of the fourth day and the following night*

The obvious drop started after 5:30 PM, again cleaner in the late afternoon and more fragmented in the evening and night, but keeping the big lines. This pattern seems to be a generality here. The continuous negative values appeared early on at 9:57 PM. This time the lowpoint of -14.6 degrees was reached earlier, around 4:30 AM as after that was a significant increase to -6.8 C at 5:30 AM, dropping afterwards back to -14 around 6 AM. Wasn’t present, but probably wind disturbance again.

Fifth day and night (21-22th September)

I was in Uyuni on this day where observed a partially cirrus covered sky, spotting a few undeveloped cumulus clouds over the mountains. From the diagram the conditions in the Alota area are still stable, this time the fast morning warming raised the temperature above 0 already around 7:45 AM.

*The temperature curve of the fifth day and the following night*

The curve follows a very similar pattern as in the previous days, reaching a little higher peak (19.5 degrees) shortly before 4 PM. Then comes the cleaner afternoon drop and the more disturbed evening and night. Reaching 0 degrees at 10:13 PM, the continuous negative values started from 11:11 PM. With a low of -11.7 C around 6 AM is still a cold morning, though less frigid than the past ones. Huge 34.1 degree daily amplitude, second biggest until now.

Sixth day and night (22-23th September)

I don’t remember the sky’s state on this day as was resting inside my hotel room most of the time (flu). The day part of the temperature curve is similar to the previous one, exceeding 0 degrees after 7:30 AM and reaching the peak of 19.9 at 2:45 PM.

*The temperature curve of the sixth day and the following night*

The night cooling is somewhat similar (more disturbed after the evening) but weaker, reaching only -6.8 degrees at 5:35 AM, preceded by some 3-5 degree ups and downs in shorter periods of time. First negative value appeared at 0:29 AM and became continuous from 1:37 AM. The 31.6 degree daily fluctuation is still solid.

Seventh day and night (23-24th September)

Except some more developed convective clouds above the mountains in the east the sky was still clear in Uyuni. It’s the warmest day of the research, the 0 degree mark was exceeded already around 7:15 AM, while the maximum climbed to 20.3 C at 1:17 PM.

*The temperature curve of the seventh day and the following night*

No significant changes in the curve’s general pattern, but the drop is even less potent this time, becoming continuously negative only from 4:49 AM and reaching a mild -5.4 C low at 6:15 AM. The 27.1 degree amplitude is less pronounced than in the previous days when it was constantly well above 30 degree.

Eighth day and night (24-25th September)

On this day I made a longer hike to Salar de Uyuni where the sky was clear, observing developed convective clouds only above the eastern mountains. However, now the air was a little dusty with less visibility than in the previous days.

*The temperature curve of the eighth day and the following night*

Again, no mentionable changes in the curve’s rising part, shortly after 7 AM reached 0 degrees and raised to 19.4 C at 1:09 PM following the general “convex pattern”. This was followed by the weakest night, the temperature becoming negative only from 5:35 AM and recording the warmest low of -4.1 degrees at 6:33 AM. This was preceded by more than 6 degree short term ups and downs, warming up to positive 9.4 degrees not long before midnight. Compared to the first days, the 24.8 degree amplitude is also modest.

Ninth day and night (25-26th September)

Another less memorable day regarding the ambience as was again mostly inside because of UV damage to my eyes (reflected rays on the saltpan), but I remember it was pretty bright in Uyuni, as it seriously disturbed my vision around midday.

*The temperature curve of the ninth day (interrupted)*

The graph shows the same clean and strong morning rise with the temperature passing over the 0 degree mark not long after 7 AM and reaching 19.0 degrees at 1:55 PM. But at 3:13 PM the diagram is suddenly interrupted. I concluded that the tripod was overturned in this afternoon by the violent westerly wind and the sensor’s cable was disconnected due to the fall.

Tenth day and night (26-27th September)

At dawn I went back to Alota by bus, where the morning was quite chilly, likely below -5 degrees. After the 20 km hike I reached the research spot before 11 AM. Fortunately the trouble caused by the wind was only temporary and the logger could continue recording the temperature after reconnecting the sensor. The day was completely clear (only some convective clouds in the far horizon above the southern mountains) but windy again in the early afternoon when I made an ascent to the peak of Jubina mountain.

*The temperature curve of the tenth day (first part missing) and the following night*

The day’s maximum was 19.1 degrees Celsius and was reached at 2:39 PM. I’m pretty sure that today the amplitude exceeded the 30 degree mark again, but having no concrete data from the night this is only an opinion. Nonetheless, I have data from the following one which was the coldest in the entire research period. The first freezing appeared around midnight, while the continuous negative values started from 0:37 AM. Despite being again less stable in the late evening and in the first part of the night when we can observe 3-4 degree short term ups and downs on the graph, the completely clear conditions favorized to descend very deep in the second part of the dark hours, reaching an impressive -19.0 degrees at 6:23 AM shortly before sunrise. This together with the previous day’s 19.1 degree maximum gives a staggering 38.1 degree amplitude in under 24 hours. The logger was stopped at 7:01 AM when the screen showed -11.6 degrees.

The average temperature of the 10 days research is 5.7 degrees Celsius. The mean minimum is -12.2 degrees, while the mean maximum 18.5 degrees, which give a mean daily amplitude of 30.7 degrees. We can observe that the mean temperature is clearly higher than we could expect solely from the minimums and maximums, which is caused by the fact that the positive part of the curve has a rounded peak, while the negative one is much sharper, technically V shaped.

General conclusions

The sky is predominantly clear both day and night, altocumulus lenticularis being the most common cloud type.
The wind follows an obvious pattern: in the night and morning is weak or calm, while the afternoon is much more windier, when the westerlies are dominating.
The daily temperature fluctuation is huge, usually exceeding 30 degrees, possibly producing one of the biggest average amplitudes on Earth.
The warming after sunrise is much faster than the cooling after sunset, regularly reaching or exceeding 10 degrees in one hour.
Regarding the finer details, interestingly the short period disturbances in the temperature’s course are always bigger in the evening and even in the night than in the late afternoon when the drop is much smoother, but it seems that this doesn’t correlates with the wind speed.
More than 1 degree fluctuations can appear often in very short periods of time even in the coldest, virtually windless mornings.
There is a clear difference between the positive (related to the maximums) and negative waves (related to the minimums) of the temperature curve, the former having a rounded, while the latter a more angled shape. That means the cooling is pretty constant until the morning without approaching an equilibrium state (very low humidity), thus, before sunrise is often 15, but sometimes even 20 degrees colder than around midnight.
Due to the elevation and the tropical setting the UV radiation is extremely high.
There is striking difference between sun and shade, without wind the same temperature feels much warmer than at sea level.

Comparing my logger’s results with the official data of the local weather stations

After finishing the research I managed to obtain valuable information at Uyuni airport meteorological station, thanks to the helping nature of the hotel staff. Below is a chart with the minimums, maximums and amplitudes registered in the same time period:

*Comparison between the researched endorheic basin and Uyuni weather station (degrees in Celsius)*

The most obvious thing is the huge discrepancy between the minimum temperatures, Laguna Seca being colder with 6 degrees on average and 8-10 degrees during the frostier days, while in the milder (less stable) ones they are pretty close to each other. There is no doubt that this is caused by the much stronger temperature inversion in the closed basin, which manifests itself during the calmer periods. Even if Uyuni too is situated on the floor of a basin, the more extensive flat terrain doesn’t permit the same level of cold air pool formation.

On the other hand, the highest temperatures are very similar on average, the closed basin being even slightly warmer despite the higher elevation, which under the same circumstances should gave him a disadvantage of around 2-2.5 degrees. This is probably caused by the stronger föhn effect in the Alota region, where the western mountain ranges are much closer and the dominant wind is blowing exactly from their direction.

Weather data of Bolivia’s official stations (Ogimet)
*Uyuni does not appear in this chart

The partially missing Ogimet data shows that Potosí weather station which is situated on the eastern part of the Altiplano and higher than Uyuni (above 3900 m) had 19-22 degree maximums in this period (likely föhn effect too), but also much weaker minimums (-3, 2 degrees) certainly due to the more exposed topography.

Regarding the amplitudes, thanks to the big advantage on the low temperature front, Laguna Seca exceeds Uyuni with a good 6 degrees, but sometimes the discrepancy can be more than 10 degrees. While Uyuni’s biggest amplitude in under 24 hours was 28.6 degrees (from 19.4 to -9.2 degrees) in the period of my research, the closed basin reached 38.1 degrees (from 19.1 to -19 degrees). No doubt that this place can surpass 40 degrees in the best circumstances. Taking into account that Uyuni has one of the biggest average daily fluctuations of all the official weather stations I’ve encountered until now on the net, a place which is regularly 5-10 degrees ahead of this definitely can be considered worth of studying in the long term. The future is open as always, we’ll see.

Evrotas Gorge: quest for a new european pole of heat (1/3)

Intro: Ancient and hardy

Laconia represents the southern portion of the Peloponnese peninsula, which itself is laying in southern Greece. Mostly remembered in association with the warrior state of Sparta (old name Lacedaemon) the region is situated at the same latitude as Andalusia in Spain, known as the hottest area of Europe. Both are stretching below the 37th northern latitude, thus slightly overreaching even some portions of the African continent. At 36.23 N, Cape Tenaro of the Mani peninsula is the second southernmost point of continental Europe, closely following cape Tarifa at the strait of Gibraltar.

*Landscape in the Mani peninsula* *near Gerolimenas*

The Eurotas (Evrotas) valley represented the core of the ancient kingdom, which between the 8-5th century BC was one of the strongest in the entire Mediterranean basin. Though there are also more fertile areas with lots of olive and citrus fruit plantations, in many parts the landscape resembles the harsh character and lifestyle of its old inhabitants. Generally, as you are moving towards the south, the more barren and rugged the terrain became, the Mani peninsula almost bordering the semi-desert. Unsurprisingly, the present residents of this remote corner, the “maniots”, pride themselves to be the descendants of the ancient spartans.

Choosing the target

Beside the historical significance, for modern greeks the Eurotas valley is also known for its sweltering summer weather. The southern setting combined with the föhn effect generated by the two bordering mountain ranges (Taygetus in the west, Parnon in the east) is responsible for this peculiarity, hence often being the hottest region of the country. In the summer the winds are generally blowing from the north (local name is meltemi), bringing sunny, hot and dry weather for many days, or even weeks.

*Relief map of the Peloponnese peninsula with the chosen spot (red dot)*

The city of Sparta is situated in the middle section of the valley around 200 meters elevation, quit far from the moderating effect of the sea (around 30 km). Depending on the sources and the measuring period it has an average July maximum temperature of 35-36 degrees Celsius, the highest in Greece and approaching the hottest weather stations in Andalusia like Cordoba or Sevilla.

The highest temperature ever recorded in Sparta is 45.7 degrees Celsius (August 2021), but according to Wikipedia another station nearby measured then above 47 degrees Celsius. In that same year and month Syracuse in Sicily, Italy registered 48.8 degrees Celsius, dethroning the old European heat record of Elefsina, Greece from July 1977. There is some controversy regarding the context of the values, as some weather stations have passive, while others fan aspirated solar radiation shields. We will discuss this in details in the 3rd part of the blog.

*Satellite image with the location of the research (red dot) inside the Evrotas Gorge*

Closer to the Evrotas river’s mouth there is a topographical feature named Vrontamas Gorge, where – as the name suggest it – the valley changes from flatter to a more rugged landscape. I chose this narrowing to be the place of my research, considering that the barren, steep walls could give a little extra to the already hot general ambience, while the sheltered, sinuous shape of the gorge can delay the onset of a hypothetical breeze.

Brief summary of the research

Originally this journey wasn’t planned to be part of the classical extreme climate research series, but the promising forecast made me to decide packing the weather installation too.

My plane landed in Athens in the evening of 15th July from where the next day I moved to Sparta by bus. Reaching Krokees settlement by taxi, on 17th July I hiked to the chosen location, first along the road, then following the course of a tributary of the Evrotas river. This latter sector was more difficult than expected, in some parts my progress being seriously limited by the combination of rugged topography (big boulders) and dense vegetation.

I started the journey by foot before 9 AM and reached the research area around 11:30 AM (between 9-10 km in all, from this 6 km in the wilderness). The sky was completely clear and already hot in the morning hours, exceeding the human body temperature well before noon. Except a single small puddle inside a cavity there was no water in the valley.

Finding a proper sheltered spot (even slightly endorheic) in the dry riverbed flanked by tall limestone cliffs in the east, the data logger was mounted on the tripod. I secured the installation attaching a sack filled with rocks to can handle also the windier conditions. The exact coordinates are 36.89839 N, 22.62521 E, the elevation 29 meters above the sea level. Shortly after 12 PM the mini weather station started its operation. First reading: 37.7 degrees Celsius.

*The weather station in the dried riverbed*

I stayed near the installation to monitor the temperature rise during the hottest part of the day live, waiting in the shade of the trees and shrubs. The maximum reached 41.1 degrees Celsius at 3:13 PM.

Before 5 PM I left the research area and returned to collect the equipment 4 days later. During this intermediate period I travelled to the Mani peninsula in the extreme south of the Peloponnesos, experiencing constant sunny and hot weather every day and observing some convective clouds only above the higher part of the Taygetus.

*The maximum (41.1 degrees) was reached at 3:13 PM*

Arriving from the southern, easier path (via Skala) in the afternoon of 21th July I found the instrument in its place and functional with all data recorded correctly. The absolute maximum reached 42.2 degrees Celsius on 18th July, surpassing the previous day’s record by 1.1 degrees. Four out of five days the temperature went above 41 degrees, while the latter one was much less hot, remaining below 36 degrees Celsius. The lowest value was registered during the last night when the temperature dropped to 21.7 degrees Celsius. I spotted clouds (cumulonimbus this time) only above the main ridge of the Taygetus again.

During both my hikes I didn’t saw any animals outside some birds and small lizards, encountering a few goats only closer to the village beside the orange plantations, where I crossed my path also with a few cars.

The instruments used in the field

-One LogTag UTRED30-16 data logger with the measuring range between -40 and +99 degrees Celsius, an accuracy of 0.5 degrees Celsius and a resolution of 0.1 degrees Celsius

-One Greisinger G1710 thermometer with the measuring range between -70 and +250 degrees Celsius, an accuracy and resolution of 0.1 degrees, used for instant hand measurements

-One photo camera tripod serving as the support for the instruments

-One helical solar radiation shield from Barani Design Technologies: https://www.baranidesign.com/

*The Barani helical radiation shield efficiently protects the thermometer’s sensor*

To be continued…

Evrotas Gorge: quest for a new european pole of heat (2/3)

Journey photo album

The statue of Leonidas, hero of the Battle of Thermopylae in Sparta. Arriving in Athens in the late evening, the next morning I already continued the journey to the Peloponnese by bus. It was around midday when I left my luggage at the accommodation and went out to experience my first dose of mediterranean heat.

*At 2 PM – purposefully of course – at the ancient ruins (no payment, it’s free)*

The main ridge of the Taygetus with strong mythological connotations is located south-west of the city. It is said that the “inapt” newborns were dropped in a chasm somewhere in these mountains and only the more sturdy ones were kept alive. While according to the actual opinions this is a fictional exaggeration, it certainly have its roots in the strict nature of the old inhabitants’s ethics.

*Beside the more robust and older Greek and Roman constructions there are also a few medieval Byzantine structures*

*A little off the path, remnant of an old wall, likely also Byzantine*

Around 3 PM it’s time for the first temperature check in the shade of an olive tree (notice the sensor above). IS THIS SPARTAAA?! Of course it is. The area has about the same summer highs as Andalusia in Spain, thus is one of the hottest places in entire Europe.

*The sunbaked olive trees maybe have some recollection of the times when this gentle prominence was an active ceremonial center*

The next morning: sunrise above the Taygetus with the pyramid of Profitis Ilias (2405 m) in the left. Today is an important day as I have to reach the chosen spot in the Evrotas gorge to place the meteorological equipment. The easiest (but not the cheapest) way is to take a taxi to Krokees village and start the hike from there. As I don’t have any time (nor energy for that matter) to waste, this is what I’ve done.

*At the periphery of Krokees around 9 AM: it’s already hot from the start, not a single cloud on the sky. The first few kilometers are on a rural road with little traffic (a few tractors).*

Agios Georgios church (according to Google Earth): leaving the asphalt I switched soon to “freestyle mode”, starting with a short-cut through the olive plantations. A valley, tributary to the Eurotas is only a few hundreds of meters away, my plan is to follow it until the confluence from where my target is close

Unsurprisingly, the valley has no water at all. In Greece, especially the Peloponnese, this is very common during the summer, the river revives only in the wetter period of the year (autumn-winter), when often becomes dangerous, flooding the surrounding plantations. But now the citrus fruits have a different enemy: drought. And I am at its mercy too.

Leonidas lost his shield: suspecting that this part will likely not be a walk in the park, I am prepared with sufficient water (6 liters) to can handle carrying the heavy luggage in the heat. The work is even harder than I thought, the combination between the rugged terrain and dense vegetation sometimes seriously limits my progress. I had to return to collect the mosquito tent (green circle in the picture) as it was often pulled out of its anchorage.

Fighting the boulder labyrinth. No idea how difficult could became later, but at this time already crossed my mind that maybe I will have to reconsider the plan to the target. The southern access through Skala village is certainly much easier. We’ll see. I like challenges, thus a return is only for an emergency situation.

I haven’t checked my GPS in the tributary valley at all. Knowing that the direction is good, I’m somehow not curious regarding the distances, but my intuition is generally positive. Though, not as much as the temperatures are…

This is the single puddle of water I came across in the entire gorge. Definitely not for drinking but very welcoming to cool off a little. There were lots of wasps around, but nobody was killed in the territorial conflict. And I am bigger.

Before 11:30 AM I’m outside the ravine and soon reached the confluence. Okay, I will say that this was “reasonably exhaustive”, satisfying my addiction of adventure, while properly preserving the energy levels at the same time.

*This must be the “Skala road”. It’s likely above the human body temperature now, we’ll see it soon.*

*Yep, the GPS is telling me that I arrived. It’s only slightly passed 11:30 AM, which considering the terrain I’ve crossed (around 6 km in the rough wilderness) is not bad at all.*

Choosing a ditch of the dried riverbed as the exact research spot, the logger was mounted soon on the tripod. Better than I imagined: the steep, barren eastern bank could add some reflected radiation to the general ambience during the afternoon.

Shortly after 12 PM the weather station started its operation. The first reading was 37.7 degrees Celsius, a decent start. The placard is in case if somebody will came across the installation, but pondering this possibility now from the spot, that looks very unlikely.

Before 2 PM the 40 degrees mark was exceeded. Already content that I packed the weather equipment in the luggage. Originally this trip was planned as a simple countryside traveling, but the optimistic forecast made me to change my mind in the last minutes. Sure, it will somehow limit my opportunities regarding the visited sights, but worth the sacrifice.

Around 3 PM, my favorite time of day in the summer: still very powerful solar radiation, while already close to the maximum thermal potential, meaning that the felt temperature is likely the highest possible. To be precise, the radiation is the strongest at noon (around 1:30 PM here) when the sun angle is at its highest (UV component = you will be sunburned), while the air itself usually will warm a little more (IR component = highest temperature in the shade) until the mid-afternoon hours (4-5 PM).

The limestone cliffs of the eastern side: changing the former resting place in the forest after the sun moved towards the west, I am waiting in the shade of a small mound covered with tall reeds, checking the temperature on the screen of the device from time to time. Still no clouds, sometimes there are a few wind gusts.

Sometime before 4 PM the temperature reached 41 degrees Celsius, I think this will remain today’s peak. Good value, tomorrow it could be even hotter. Before 5 PM I packed my luggage and left the research area. The original plan was to camp nearby, but I changed my mind to continue the hike to Skala village.

*The riverbed is covered in some kind of “weird veil”, which I suspect to be dried algae*

*Still very hot around 5 PM, but as I thought, the path is much easier here, thus my progress is good*

*Looking back: after a few km the valley broadens. I heard that during the winter rains the Evrotas can turn into a raging torrent, destroying the plantations on its banks. I can imagine that.*

*Some caves on the eastern side, soon I’m out of the gorge*. After a short, wilder portion in the beginning, the track followed a dirt road along the orange plantations. Except a few birds, small lizards and the noisy cicadas I didn’t observed any living creatures during my hike, spotting a few goats and 1-2 cars only closer to the village.

*With sufficient water reserves remaining, shortly after 6:30 PM I reached Skala*. *But I hope to drink something else, not the 40 degree bathwater in my backpack. That something else happened to be **Monster energy’s “the doctor”** version. And yes, it cured me.*

The beach between Skala and Gytheio. Long story short: after refueling in Skala, heartened by the less severe temperatures of the approaching evening, I decided to camp on the nearest shore, taking a bath in the sea after this long, hot day. While easily completing the additional 6-7 kilometers on the straight asphalt road, I observed after arriving that my tent is missing. No way! After successfully getting through the wild gorge, I lost it here on the highway? I can’t stay here for the night. The beer was good, the bath even better, but after sunset the attack of the mosquitoes was relentless. I have to return to Skala and sleep in a hotel. This is what I’ve done, unfortunately my headlamp couldn’t spot the lost article along the road. Good night.

The next day in Gytheio, the port of ancient Sparta (Profitis Ilias in the background). The picturesque coastal town (a little too crowded for my taste) is closely related to the story of the Trojan war, as it’s the place where Paris and Helen spent their first night before the departure to Troy. It was also famous in the antiquity because of the purple-dye snails (murex), the marine animal from which the expensive dye was extracted.

The lighthouse (don’t confuse it with the one at Cape Tenaro) sits at the end of a thin promontory. The surface of the rocks along the coast is very sharp, but of course this didn’t stopped me to enter the balmy waters. Soon I will continue the journey to Gerolimenas, which is the final station of the Laconian buses. Already very hot, I measured 37 degrees in the shade at the bus station.

The tranquil bay of Gerolimenas: I prefer it over the more touristic Gytheio. Buying some provisions in the supermarket (the last one in southern Mani) I continued my journey on the road by foot towards Kyparissos.

*Just a little outside the settlement I got the first glimpse of the Tenaro lighthouse,* *my next main targe*t. The landscape of the Mani peninsula is more barren, resembling a semi-desert, only the blue sea is the constant reminder that you have some retreat options in case the sun is too harsh with you. But you will not have any available drinking source nearby, so careful with the planning.

*At ancient Kenipolis: this place was a colony of Tainaron (Taenarum). It’s time for another bath.*

*There are only a few accommodations in nearby Alika and Kyparissos and none of them is cheap. The sea is free.*

*Close to the water, because of the higher humidity, the same temperature feels hotter than more inland*

*Porto Mani suites. Because of its “strategic placement” on the way to the southern cape, I will spend the following night in this nice traditional complex. Forget the price, its a must.*

*While you can hear them almost everywhere, representing the constant background noise of the greek experience, you can rarely spot the cicadas*. *Must be kind of a “Pavlovian reflex”, as for me it’s closely associated with the heat and sunshine*.

*And why not a third bath at the private beach of the residency*

*Sunset from my balcony. It was another hot day and tomorrow could be the hottest one on the narrow peninsula*. *That means I have some homework to do, as the longer hike, including the trip to the cape was planned for 19th July.*

*Complete lack of clouds both day and night*, *entering fairytale level*

*You can observe this small rocky outcrop situated about 5 km from the shore, first to the south, then to the west, starting from Gerolimenas until passing Marmari beach (big zoom of course)*

*Ready? Hell yeah! Already above 35 degrees after 9 AM*

After a tasty breakfast at the accommodation I started to climb the serpentines towards the fortified village of Vathia. Excellent vibe in the atmosphere, the above average heat only intensifies the experience.

Cutting the last big curve on the road I approach the ghost-town on a secondary path. Founding the gate closed, I enter the area along the old walls, meandering and climbing between the dusty architectural elements.

*Time for hydration. New tempcheck in the shade of the marble monument*

Classical view of the fortification. The now abandoned settlement is one of the most known tourist attractions in Mani, which sits around 150 meters above the sea level. You can stop for a drink at the nearby taverna.

Spotless sky: this is the real face of Mani. If the visual component can’t satisfy you enough, there is also the olfactive one, as the air is filled with the emanations of the local aromatic herbs (salvia dominates)

*Though not too close to the coast, there are many boats of different sizes on the sea*

Sharp contrast between the arid, sunbaked land and the turquoise waters of the sea. The latter is very inviting, I feel a little seduced like Odysseus was when became the “hostage” of Calypso on the island of Ogygia. No, I have to continue.

*Next hydration stop at one of the very few shaded parts of the southern road*

*A lot of signs for a single person*. Yes, *I am approaching.*

*I took the road towards Mianes village (haven’t seen locals there) to do the last part of the hike along the ridge, thus above the classical track*

*Resting in the shade of some old walls. The heat started to affect me, until now the enthusiasm is already mixed with tiredness*

On the final ridge. Exposed on the rugged terrain in the phrygana, being at the mercy of Helios, the last section demanded my full attention. I can’t stop thinking about the dive I will take after reaching the target.

*Somewhere below me on the right is the mythological “Cave of Hades”, a gate to the Underworld, the shady place from where only a few (like Hercules, Theseus and Orpheus) returned alive*. *At the moment I feel some weird inclination to enter that shady place…*

*Kokkinogeia, the last inhabited place left behind on the left*

Shortly before 1 PM I reached the secluded building of Cape Tenaro. At 36.28 N, this is the second southernmost point of continental Europe (after cape Tarifa at the Strait of Gibraltar). Here I am slightly closer to the Equator than two African capitals: Tunis and Algiers. *Built in 1882 by the French, for a few decades the lighthouse is automated, thus uninhabited, adding to the feeling of isolation.*

*The tempcheck in the shade of the northern wall is a must before entering the tempting waters*. *The southern setting means that in the summer the sun angle is very high here and now it’s exactly around midday. I have to confess: it was premeditated again.*

*This is the exact spot where the last strip of land meets the mighty sea, from here the Lybian coast is closer than Mount Olympus*

*That was expectable. A little warmish, but definitely welcomed in these circumstances.*

The most enjoyable part was just simply floating on the surface with the face too submerged in the water, observing the shadow of my body on the bright turquoise background, while feeling the energy levels returning to normal. *Maybe Homer was wrong and the Underworld is somewhere else.*

*The Zobject has no zobjections as well*

I observed a single person on the trail returning from the pharos when I was high on the ridge, but spotted nobody after that. However, I saw a few smaller boats passing. One of them stopped pretty close, so we could conversate. They asked me if everything is fine and tried to tell me that there are some “underground dangers”, including sharks. Maybe this last one was only added to scare me as they couldn’t explain properly about the real problem, the currents, which can take you off the shore if you distance yourself enough. Sure, I don’t have plans to cover the 380 km to Cyrenaica.

*To reach the sea at the very end you have to descend another vertical 30 meters between the huge boulders, my favorite sector*

*Phrygana vs thalassa: the view to the right (east) while returning*

*This time on the classical, old rusty trail, heading to Kokkinogeia. To its taverna to be precise.*

After two cold beers I visited the nearby sanctuary of Poseidon, the god of the sea venerated in ancient Taenarum from which the cape got its name. Beside the mythological aspects, in those times the place was famous also because of the precious green marble. *The present construction is actually a Christian church built in the Byzantine period from the rocks of the older Greek temple.*

*This small cave situated on the shore of a protected bay close to the temple is known as an old ritualistic place related to the mythology of Hades*. *The guardian monster, Cerberus wasn’t present, the entrance was protected by some tanned western pensioners.*

Around 6 PM it was time to leave the southernmost village. Today and tomorrow I will stay in a traditional maniot stone tower in Palyros, another barely populated hamlet located at the very end of the old continent.

*View of the teal-colored Vathi bay on the right of the road. Its name, which means “deep” in greek is very common in the Mani peninsula.*

*Arriving in Palyros, situated pretty high up on a hill about 150 meters above the sea*

*After a warm welcome and a tasty dinner (moussaka with tsatziki, what else), sitting on my balcony*. *In Mani the stone towers are a very common sight. Many are abandoned, some inhabited, while a few (like this one) can be rented by travelers.* *Built in the times when vendettas between rival families were common, now the general atmosphere is more peaceful.*

*I live in the room just above the entrance on the left, while the local family resides in the higher parts of the tower on the right. This picture will have some significance later on.*

*The next morning: view of the eastern “pseudo cape” – as I named it – with Kourelos, a neighboring hamlet above. My host, mr Panos told me that he grow up there.*

Some horses grazing near the sanctuary of Poseidon on the fringes of Kokkinogeia, with the “famous” southernmost parking lot on the right. Today I have a serious objective in my mind: finding the gates of Hades!

*I formerly identified this crack on Google Earth on the shores of the “pseudo cape” peninsula*

*Not Cerberus this time either, but still a little suspicious*

To reach the other cavity, the one which according to the locals is the actual Cave of Hades I have to return to the parking lot, then cross the ridge towards the west. It’s not far, just a little rugged and thorny.

*I think it is a little farther on the right*

Yep, this is the place. As here the surface of the rocks right at the sea is very sharp, I couldn’t enter the water with the camera to take photos from inside. But even beyond this obstacle the highlight of the experience would’ve been remained out of the reach: *there is a small chamber accessible through a narrow, short and low passage, what you can enter the easiest way by swimming underneath*. *The ceiling is not dangerously close during calmer waters like now, but can certainly became a threat when the sea is more turbulent.* *Inside there are two head-sized stalactite structures, one of them right above your shoulder so you can use it for stabilization while enjoying the view towards the stripe of light outside*. *Then you swim back underwater in the bright blue mass surrounded by small fishes.*

*Before Poseidon became the patron of the area, it is said that the sun god was venerated here. There is a reference to this in the Homeric Hymn to Apollo, which recounts:*

“…and by the Laconian land they came to a sea-crowned city and the place of Helios who delights men, Tainaron, where the deep-fleeced sheep of lord Helios always graze and inhabit a delightful spot…”

*The so called “Star of Aria” dates from a later period (1st century AD) and it’s part of the mosaic floor of a former roman villa*.

*Sage (salvia officinalis) on the roadside, the “olfactive leitmotiv” of the maniot experience*

Porto Kagio, a tranquil resort with good tavernas. It sits just below Palyros, but you have to go round on the asphalt road as the thick phrygana vegetation will convince you to forget about a shortcut.

*After a relaxing swim followed by a tasty fish meal I am heading back to the stone tower*

My room is comfortable and quiet, but has a “dark secret” which I didn’t know beforehand: there is a single key which opens it and that key is the one I received at my arrival. No, I didn’t lost it, but left it on the inside and the air-blast slammed the door. Nobody can open it. Maybe we could enter it through my balcony, thus a ladder is brought. Bad luck, the balcony door is also closed. As it’s already dusk, the temperamental Panos is a little worried.

Maybe through the bathroom window? Fingers crossed, hopefully I left it open. Bingo, we are saved! The enter itself demanded some contortionist skills, but it was my time to redeem the bad karma. Changing from front to back posture, using some accessories of the bathroom’s interior as grips, I safely landed inside.

The team (all one family) with Panos in the center. The attained luck continued to follow me the next day as my host traveled to Athens, thus could take me to Gytheio. From there I had to take a taxi to Skala again to start the hike towards the Evrotas gorge. Kostas, the driver didn’t speaks english, but he is good with numbers: after showing me 25 on the phone’s screen, he was more than happy with my 20+10 bill and didn’t want to understand my body language regarding the change: “No, no, no my friend, it’s enough-it’s enough, thank you very much!” Avoid Kostas at all costas, guys.

On the way to collect the meteorological equipment. Today is less hot than all the previous days, I felt it both near the coast and farther inland. Some less developed cumulonimbus clouds appeared above the Taygetus, otherwise still sunshine everywhere.

I reached the research area around 3:30 PM. Of course, nobody was here, the installation is intact. From this point you can observe the slightly endorheic nature of the ditch where the data logger stayed as I took this photo standing “downstream” from the tripod.

*Observing the milder temperatures, respectively the fact that has the tendency to did not rise farther more, I stopped the device after 4 PM*

Good result, it was worth the effort to take it with me. As I expected, the maximum was recorded on 18th July, while the minimum in the last night. Four out of five days the temperature raised above 41 degrees Celsius. Curious to compare it with the values registered at the nearby official stations.

*Due to the less hostile ambience, the return was less strenuous than in the day of the installation*

Bridge in the central park of Skala: time for another cold **Monster – the doctor**

Trying to avoid Kostas I went out to hitchhike, but it seems that everybody supports him and not me. The evening was approaching, thus after more than an hour on the roadside decided to accept again the taxi version. A helpful local waiter called for a cab and soon I was in Gytheio. It wasn’t Kostas and the price 25-2=23

*Profitis Ilias watching over the lively, romantic resort*. *Spending the night in a decent hotel right above the seaside promenade (a little noisy until the night, otherwise ideal for a solo traveler), the next day I had to return to Athens.*

Inside a church in Tripoli, central Peloponnese. In the morning I made a rapid itinerary change deciding to visit Argos. There are many buses from there to the capital, though not sure how many are that way. It turned out that there are only two every day, starting from Tripoli, the center of Laconia. Every region has its own company and the link between them is less frequented. The bus first went to Nafplio, the old greek capital, then another one continued to Argos.

I decided to get off at the ruins of ancient Tiryns, hometown of the mythological hero Heracles, also known as Hercules. The place seemed empty and closed (maybe renovation?), thus I made another change in the plan: crossing the fence.

*An intruder inside the cyclopean walls. Still waiting to spot other visitors, which would mean that the site is open but the entrance is on the other side*

*Nope, the former mycenaean complex is completely mine*

*Actually I was right, the entrance indeed is on the other side. But the placard showed that the closing time is 15:30, that was about 10-15 minutes before my arrival.* *Not my fault.*

From Tiryns I walked 9-10 km to Argos on the very flat and straight main road. My plan is to reach the castle of Larisa, which is high up on a hill. Locals told me there is no other way, you must go round along the asphalt. After the first 1-2 km I couldn’t resist the temptation to try a shortcut across the olive plantations. Though sweating more, it saved some time to *comfortable catch the last evening bus to Athens.*

View from the citadel towards the north. The construction dates from the Byzantine times (12th century), but there are also ruins from the antiquity on another smaller hill nearby. The two were connected at a certain time as the city has a very tumultuous history starting from the earliest periods. I heard that even in our times still exists some kind of rivalry between Argos and Sparta, *ironically including even the battle for the title of the hottest place in Greece as both have their maximum around 46 centigrade.*

*Descending under the Argive walls, looking towards Mycenae. How to finish it better?*

To be continued…

Evrotas Gorge: quest for a new european pole of heat (3/3)

Interpretation of the logger’s graph (using LogTag Analyzer 3 software)

*The temperature curve of the 5 days/ 4 nights research period. The device was registering a value every minute.*

First day (July 17)

Hiking under a sunny sky I reached the research area before noon. The weather station started its operation at 12:11 PM when the screen of the logger showed 37.7 degrees Celsius. As I set the device for 1 minute logging (short intervals) the curve has the typical “saw aspect” with many small ups and downs inside the general “big waves”.

Until 1:53 PM the temperature climbed to 40.9 degrees, then at 3:13 PM reached the day’s maximum: 41.1 degrees Celsius. I left the installation before 5 PM when it was still slightly above 40 degrees and returned here only in the last day (21th July) to collect the equipment. During my staying the sky was completely clear with some short term wind speed intensifications.

*The temperature curve of the first day and the following night*

The graph shows that a more abrupt descent started at 7:15 PM in the evening when the temperature dropped from 37.2 C to 22.1 C until 5:02 AM. Afterwards there is an anomalous rise to 29.5 C until 6:20 AM, followed by a secondary morning drop to 23.8 C at 7:03 AM, certainly caused by wind.

Second day (July 18)

This was the hottest day. The temperature exceeded 40 degrees at 12:06 PM and continued to rise until 2:52 PM when the highest value of the 5 days research was recorded: 42.2 degrees Celsius. The 40+ heat was present until 6:30 PM and the more abrupt descent started at 7:51 PM when dropped from 37.8 C to 26.3 C until 10:55 PM.

The next 20 minutes represents the biggest anomaly of the entire measuring period as until 11:18 PM the temperature rapidly climbed back to 34.5 degrees, maintaining the unusual warmth until 2:07 AM in the night when still were 32.6 degrees. Afterwards dropped to 26.6 C until 2:55 AM, but then raised again to 33.5 C at 5:31 in the dawn. Very chaotic night pattern for sure.

I was in the Mani peninsula at Kyparissos at that time and measured an unusually high 34 degrees around 7:30 in the morning. As I observed no clouds at all in all directions, there is no doubt that all these extreme fluctuations were caused by wind.

Third day (July 19)

Another very hot day. Reaching 40 degrees before 12:30 PM, the temperature was rising until 3:08 PM when 41.8 degrees Celsius, the day’s maximum and the second highest value of the research was registered. It remained above 40 degrees until 6:06 PM, while a more abrupt descent started after 8:30 in the evening when dropped from 35.3 C to 29.3 until 9:26 PM.

Then a very similar to yesterday’s “out of the nowhere” kind of rise happened, thus in only a few minutes it warmed back to 33.8 C. Following another two sharp ups and downs during the night, it cooled down to 26.2 C until 1:20 AM, only to climb back again to 31.5 degrees at 6:37 in the early morning. I was in the cape Tenaro area during this time and experienced constant hot and sunny weather with mild to moderate wind.

Fourth day (July 20)

Generally, the temperature was steadily rising from the morning until 1:54 PM when the peak of the day, 41.2 degrees Celsius was registered. With a few drops between, this value was reached again at 2:29 PM. It went below 40 degrees after 4 PM and this time the night cooling has a more typical aspect, without the extreme fluctuations like in the case of the previous two.

The minimum of the morning and also the lowest temperature of the research was 21.7 degrees Celsius, registered at 6:43 AM. Still in southernmost Mani, I measured below 25 C on the balcony of my room in Palyros village, definitely cooler than the previous morning when it was around 28 degrees. The sky remained completely clear day and night.

Fifth day (July 21)

Today I traveled back to collect the measuring equipment, reaching the area of the research around 3:30 PM. It was less hot than in the previous days, both in Gytheio and here in the Evrotas valley. I observed cumulonimbus clouds above the Taygetus mountains, but except that the sky remained completely clear.

*The temperature curve of the fifth (last) day*

The graph shows that after a peak of 35.8 degrees Celsius at 12:25 PM the temperature entered a slow descent phase reaching 33.8 C at 2:24 PM (probably sea breeze), then stabilizing more or less around 35 degrees. Observing the constancy of the milder conditions I stopped the data logger after 4 PM.

The average maximum temperature of the five days research period is 40.4 degrees Celsius, while the average minimum of the four nights between is 24.1 degrees Celsius, giving a mean daily amplitude of 16.3 degrees. The biggest daily fluctuation was 20.1 degrees and happened on the second day when the temperature raised from 22.1 to 42.2 degrees Celsius.

General conclusions

The sky is usually clear both day and night, convective clouds can appear mostly only above the taller mountains.
The temperature rise during the daytime is quit regular, typically reaching the maximum around 2-3 PM, but sometimes is affected by the sea breeze, which can stop the rise earlier.
The late evening and night hours can have a very chaotic course with significant fluctuations in very short periods of time due to local föhn winds, which easily disrupt the nocturnal cooling of the valley.
The daily amplitude is medium to high (14-20 degrees) facilitated by the subtropical latitude and very dry conditions, but limited by the earlier mentioned fönh winds.
The short time temperature fluctuations are much bigger during the dark hours, reaching 8 degrees in 20 minutes.

Comparison with the hottest areas of Greece and Europe

According to Ogimet, two greek weather stations exceeded the maximum recorded by my installation in the gorge of the Evrotas river. These are Serrai (Serres) and Kalamata. The former is situated in the north of the country and due to its more inland location it is indeed often very hot, likewise Demir Kapija and Gevgelija in nearby North Macedonia or Sandanski in south-western Bulgaria.

This summer’s heatwave was especially strong in the central and northern Balkans including the country I live, Romania. In these areas the thermal anomaly reached or exceeded 10 degrees sometimes, thus the usually hotter Peloponnese had a hard time keeping up with the northern neighbors sitting right under the center of the heat dome. More stations in Romania, including the capital București reached 40-41 degrees, while northern Macedonia exceeded even 42 degrees Celsius in this period. Albania, Serbia, Moldova and Ukraine also went above 40, breaking or approaching the older records.

*The maximum temperatures in Europe on 18th July*
*(the date on the image refers to the previous 24 hours)*

Kalamata (known for its tasty olives) is situated in a protected bay of the southern Peloponnese, which likely experiences the hottest weather during strong north-eastern föhn effect, when the wind is blowing across the Taygetus, annihilating the sea-breeze. I checked the Ogimet statistics (see the chart below) and yes, that was the case, during the hotter part of the day the wind was coming across the high mountain.

*The statistics of Kalamata HNMS weather station for 18th July (Ogimet)*

We have to mention here that Greece has two different weather monitoring networks: one of them is the HNMS (Hellenic National Meteorological Service), which uses passive solar radiation shields and the other is the NOA (National Observatory of Athens), which uses fan aspirated ones instead. The stations appearing in the Ogimet statistics are from the HNMS, thus the ones with classical multi-plate shields.

At the present moment it’s well documented that during strong solar radiation with little wind the passive shields can’t protect the thermometer’s sensor from overheating as efficiently as the fan aspirated versions and are outperformed also by the helical Barani shield, the one which I am using. More than that, I heard a local specialist mentioning that there is a huge discrepancy specifically between the two weather stations (HNMS vs NOA) of Serres city, the one using passive shield having a higher average maximum in the summer with up to 2 full degrees (!), which backs up my intuitive skepticism regarding the “sticking-out nature” of the related Ogimet statistics.

Note: This part will remain open for update in case of obtaining some valuable info regarding the measurements of the two hellenic weather networks. I am especially curious of the NOA statistics of the hottest stations during the 17-21 July interval. Until now I found a single one, which is that the messenian Skala village (north of Kalamata) measured the highest temperature in Greece and that’s 43.1 degrees Celsius. This is interesting as conflicts with the slightly higher value of Serres appearing on Ogimet. Let’s wait for the clarifications.

*Update on 5th September 2024:

Thanks to a local specialist I received complete monthly data sets, which are more than interesting in the context of my own measurements (see the charts below with the 5 related maximums inside the red rectangles):

And below are the extreme values recorded at my location:

What can we conclude from this?

In a nutshell: I have to correct my less optimist previous statement (read the last chapter) regarding the thermal advantage given by the small scale topography, as my location seems to be hotter with over 1 degree than both Sparti and laconian Skala settlements (which are pretty close to each other for that matter). The exception is the last day (21th July) when the breeze affected the lower course of the Evrotas but not the more inland located Sparti city.

More concretely: On 18th July (the hottest day at my weather station) the advantage was 1.8 C over Skala NOA, 1.6 C over Sparti NOA and 2 full degrees over Sparti HNMS meteorological station. The average advantage for the four hotter days is 1.4 degrees over both Skala NOA and Sparti NOA and 1.5 degrees over Sparti HNMS station. Taken into account the relatively small distances inside the same basin and the fact that my research spot is located between the two settlements we can assume that the obvious positive gap can’t be accidental.

-end of update-

Could the Evrotas gorge be the hottest place in Greece?

I think the correct answer to this question is possible with the mention that the general setting (southern placement, low elevation, sheltering mountains and some distance from the sea) is the main cause and the smaller scale topography (surrounding steep slopes) is much less relevant.

While far less impressive as in the case of a “cold trap” (known as frost hollow), where the simple law of gravity can create huge differences between the bottom and rim of a small closed basin, I think that a hypothetical “heat trap” with measurable enhancing properties could be possible with some specific topography, but due to the simple fact that the warmer air has the tendency to rise, not to sink as the colder one, it’s certainly much more difficult to “balance the ingredients” in the proper way to attain it. Maybe a future project.

Karagiye depression: below sea level, above human body (1/3)

Intro: sea or lake?

Despite the name, the Caspian Sea actually is a big lake, as it is completely landlocked, without a connection to the oceans. Beside its huge size (with 371000 square km is the largest lake in the world by far) owns another peculiarity: it lies 28 meters below the mean sea level. Even if it is situated in an arid climate, the salinity is much lower than in the oceans (about one third), mainly due to the fresh water influx (Volga river). Around the lake, especially in the northern sector, there is an extensive sunken plain area named “the Caspian Lowland”, a sparsely populated flatland covered with xerophyte shrubs and grass.

“Skal’naya tropa”, the rocky coast of Aktau

Centered around the oil industry, the city of Aktau lies on the eastern shore of the “sea” and is the capital of Mangystau region in south-western Kazakhstan. In the summer the climate resembles the mediterranean one (warm to hot with little rainfall), the coast being frequented by locals in the holidays. International tourism it just started to develop, hence is a great option for those travelers who want to have a unique and less crowdy beach experience. Above the specific “soviet background” (wide streets, rectangular structures, heroic memorials) the present day Aktau presents a peaceful atmosphere, trying to connect to the western standards.

Choosing the target

Compared with my usual work ethic regarding the extreme climate research, this travel wasn’t planned well ahead, instead was closer to a “last minute” decision. With less free time available I chose a somewhat “easier target”, both physically and financially.

Having a particular bonding with the lowest dry lands by a lifetime, the Karagiye Depression in south-western Kazakhstan popped up as the best choice in this more limited context. The bottom of the semi-desertic depression lies at 132 meters below the sea level, representing the lowest point of Kazakhstan (also the former Soviet Union) and position oneself fifth in the world after the Dead Sea (Israel-Jordan), Lake Assal (Djibouti), Turfan basin (China/ Xinjiang) and Qattara depression (Egypt).

The Karagiye Depression (red arrow) situated inside the Caspian Lowland (dark green, upper part of the image)

From the viewpoint of the hottest places of the Planet in the absolute sense can’t be considered a “top-notch” location, but taken into account its relatively high latitude (43 N) in the summertime has a decent delivery potential. The proximity to the coast (20-40 km) doesn’t really affect the daytime heating as the Caspian has a quite continental ambience and the sea-breeze is often completely annihilated by the dry easterly winds blowing from the inland deserts.

Soviet military topo map with Karagiye (center) and Aktau (formerly Shevchenko) in the north-west

Moderated by the sea, Aktau itself has an average summer maximum of around 31-32 degrees, with the absolute record of 44 degrees Celsius measured in the month of August (according to Wikipedia). I have no access to the weather statistics of the more inland locations in Mangystau and I’m not even sure there are real weather stations outside the regional capital in the closer surroundings.

The place has a peculiar topographical setting, being a “depression inside a depression”, as the nearby Caspian Sea itself is already situated below the level of the world ocean, while Karagiye lies another hundred meters lower than the big lake.

Satellite image with the location of the measuring equipment (red dot) in the north-eastern part of the basin

Regarding the exact location of the research I’d chosen a spot which is the farthest possible from the coast (37-38 km), while at the same time being at the lowest elevation (-132 m). Also, I’ll try to place the tripod on sandy surface, as it can slightly enhance the daytime heating compared with the more compact clay or the highly reflective salt crust (white patch in the above image).

The low-point can be reached the easiest way from the Aktau-Zhanaözen road (new turkish asphalt), from where it is about 10 km to the south, south-west, lying at the foot of the steep eastern rim of the basin.

Brief summary of the research

My plane landed in Aktau on 11th August in the early morning, just before sunrise. The optimistic forecast rushed me to reach the bottom of Karagiye and place the measuring equipment as soon as possible. Everything went fine, the locals were helpful and even if I slept close to nothing during the flight journey, the quick preparation was efficient and around 9 AM a car left me on the Zhanaözen road right at the viewpoint to the depression, from where I started the hike towards the bottom.

Before 10 AM it was already hot, the sky completely clear and only weak wind. After meandering my way through the fragmented escarpment, I reached the flatter part and continued the walk, crossing the sometimes harder clayey, other times more squashy salty terrain with generally sparse vegetation cover. Finding a proper sandy spot on the bottom I mounted the data logger on the tripod around 12:30 PM. The exact coordinates are: 43.490923 N, 51.838903 E, the elevation -130 m. The height of the sensor from the ground is around 170 cm. At 12:42 PM the weather station started its operation. First reading: 36.6 degrees Celsius.

I waited near the equipment until 5 PM, to monitor the temperature rise during the hottest part of the day. The maximum reached 40.1 degrees Celsius at 4:48 PM, while I randomly measured 64.3 degrees soil temperature around 1:30 PM during the highest sun angle. Before leaving I secured the tripod attaching a sack filled with soil fragments to can handle also the windier conditions.

I’ve spent the night in a mosquito tent less than 1 km from the weather station, next to a consolidated sandy pile. Despite the clear skies, partly because of the wind, the evening was warm and the night’s minimum dropped only to 28.9 degrees Celsius. I left the research area at dawn and returned to collect the equipment four days later, on 16th August in the afternoon. During this intermediate period, beside Aktau, I travelled to other locations of the Mangyshlak peninsula (Shetpe town, Caspian coast), where encountered similar dry and hot conditions with little to no clouds.

The maximum (40.1 degrees Celsius) was reached at 4:48 PM

On 16th August I crossed the Karagiye depression, starting the hike from the other side (Kuryk road), reaching the study area after traversing the salt pan situated at the very bottom. The weather was mostly sunny but somewhat less hot than in the first day, though still far from comfortable. I found the instrument in its place and functional with all data recorded correctly. The absolute maximum surpassed by half a degree (40.6 degrees Celsius) the first days peak both on 12th and 13th, while the weakest maximum happened on 15th (36.0 degrees). The lowest value was registered on 16th in the morning, when the temperature dropped to 19.3 C, by far the coldest night.

During my staying in the depression I encountered a few gazelles, camels and horses, respectively birds in the more vegetated parts. Small lizards, a few bugs and a species of spider (night time) was also present. There were no humans in the entire area between the two asphalt roads (Zhanaözen and Kuryk).

The instruments used on the field

-One LogTag UTRED30-16 data logger with the measuring range between -40 and +99 degrees Celsius, an accuracy of 0.5 degrees Celsius and a resolution of 0.1 degrees Celsius.

-One Greisinger GMH 2710-T digital precision thermometer with the measuring range between -199.9, +200 degrees Celsius, an accuracy of +-0.1 degrees Celsius and a resolution of 0.1 degrees Celsius.

-One photo camera tripod serving as the support for the instruments.

-One helical solar radiation shield from Barani Design Technologies: https://www.baranidesign.com/

To be continued…

Karagiye depression: below sea level, above human body (2/3)

Journey photo album

My plane landed in Aktau shortly before sunrise and I had the luck to catch a glimpse of the Karagiye salt flat (whitish patch below the horizon) while approaching the Caspian coast

The first impression of Kazakhstan was very positive and not only because of the sunny weather, but also the openness and helping attitude of the locals

Thus, with the assistance of the airport taxi driver who understood and was ready to help me with the basic preparations in a fast and straightforward manner, I managed to reach the starting point of the hike at the “Karagiye viewpoint” situated about 55 km distance from the city on the Zhanaözen road around 9 AM

Packed with 9 liters of water and sufficient food, at 9:30 AM I started the descent towards the bottom of the depression

The first part of the route is given by the steep ledge of the plateau, which drops in more steps, separated by flatter terraces, a prehistoric and dramatic landscape with the aspect of a labyrinth. The dominant rock type is clay and marl, generally quite friable

Around 10 AM it was already hot and the absence of the wind inside the gullies made the solar radiation even more pronounced. I am content, this is what I came for

Some gazelles wandering in the wilderness

Reaching the flatter bottom part (already below -100 m elevation) I continued the hike, turning to the south-east and generally following the line of the escarpment. In some parts there was some vegetation…

…while in other parts it was completely missing, the landscape resembling the surface of the Moon

Even here you can see sometimes the signs of life, this bird certainly came from the neighboring greener areas, where he/she resides

Here and there the monotony of the flatland is interrupted by a few consolidated sandy piles

After 12 PM I reached a spot which I consider proper to place the tripod with the attached logger. This is a smaller sandy “island” situated at the edge of the extensive clayey bottom (the GPS shows around -130 m), which could slightly enhance the daytime heating as compared with the more compact or reflective surfaces

At 12:40 I started the logger. For a short period there was some trouble as the sensor’s contact seemed to fluctuate, but luckily, after a few attempts I managed to solve the issue

The Barani helical radiation shield warrants for the efficient protection against the sun, providing both shade and sufficient ventilation to measure the actual air temperature

Soil temperature around 1:30 PM, the highest solar angle

Unlike the dusty and squashy one, this surface is particularly hard and rough

As I had both enough time and energy, without the luggage, I made a small bypass to the last visible sandy pile situated more inside the depression (around 1.5 km from the camp), which has on the top a small lookout tower

I was a little surprised that I couldn’t observe from here the white expanse of the salt pan, probably still too far with such a small elevation advantage

Back to the camp: the temperature is rising

As I lost my “legionary hat” before embarking in the minibus in Aktau, I’ve used a white T-shirt for protection against the insolation. I am sitting in a small camping chair without any shade, determined to wait here until the peak-heat

No ice cream on this beach. At least I try to protect the bottles from the relentless sun. Even without a complete greenhouse effect, the water is already unpleasantly warm, certainly above the human body temperature

Sometimes there is absolutely no air movement

That’s it! Just before deciding to leave I saw that the max went above 40 degrees

I secured the tripod with an attached sack filled with earth to can handle also the windier conditions and after 5 PM I left the weather station

Finding shade behind a neighboring conical structure I rested some time before setting my camp for the night

Even if the temperature was still high, the atmosphere started to be more bearable after the solar angle became lower

The billion-star hotel is waiting for me

Nothing on this image outside the dark sky, right? Well, almost nothing. Actually I took a picture of a bright, moving line composed of 22 light spots (still very hazy, but a zoom will help). The “UFO” was heading straight and the distance between the lights wasn’t changing, nor were they pulsing, the direction approximately NW-SE. The interesting part is that I read a short mention somewhere on the net, that in the Karagiye area the UFO encountering isn’t rare. I never saw something similar, according to a friend they must be a cluster of satellites, before diverging

Before leaving I went back to the tripod to check the minimum temperature. The night was warm, but not on the side of uncomfortable, actually almost optimal for just laying without a sleeping bag in the airy mosquito tent

Though I wasn’t taken away by E.T. , was bitten by a few mosquitos through the mesh. Fortunately not by him. You can easily spot this spider in the dark, as his eyes are reflecting the light of the headlamp

In the dawn I continued the hike back, towards the asphalt road

Not legit UFO’s, but they too can trick your imagination

For the sake of the adventure, I took another way to reach the road. Yesterday I hydrated myself properly and left sufficient water for today’s part. The milder morning temperatures are helping to accumulate some km’s before the sun hits you

I saw that there is some lush vegetation inside a canyon-like valley and was curious about the details

Water! There is kind of a “canopy” mainly composed of reeds, which hides the stream underneath, thus at first you can only hear it. The bush is so thick and tough, it can support your weight above without risking to fall through. Certainly not for human consumption, but great for a bath

This band of reed is one of the most difficult to cross terrain I’ve ever encountered. Not even tried to follow it upwards, outside the small excursion to check the water

Aha! So this is the mysterious source. Surrounded by camel dung, it’s smell was caused also by its own composition. It’s a thermal spring with evident sulfur content

Looking back towards the depression (the “reed-canyon” is visible)

The road is farther on the plateau, I guide myself following the tall electric poles in the distance

Successfully hitchhiking from the asphalt, around 11 AM I was already back in Aktau

After reaching the beach I followed the coast towards the rocky escarpment , named in russian “Skal’naya tropa”

This scenic stretch of land, what could be named “kazakh riviera” is very popular among the locals, many people are coming here from the far eastern side of the country (Astana, Almaty) – mostly by train – to spend the holidays in the mediterraneanish climate of the Caspian Sea

Arriving at my hotel, just to change my clothes and eat…

…then heading back to the city to don’t miss the splendid weather. It’s particularly hot today, but with the beach not far away I consider it just right, especially as the water temperature is quite cool (21-22 degrees Celsius)

“A soviet man standing next to some soviet camels under the soviet sun”, that’s what youtuber Bald and Bankrupt would probably say 😉

The next day I travelled to Shetpe settlement by train (about 2 hours) to visit the nearby spectacular inselbergs. The train station is pretty far from Aktau’s center, actually in another town named Mangystau. Better book it online in advance (it’s cheap) as in the summer it can be full (it was). When I got off the train I was a little surprised to not see anybody asking me to take a taxi. Okay, I’m first time here

However it was a guy, who I think was waiting for the exact same thing to happen (unsuspecting tourist alone) and pretended he is just there by chance while I packed my luggage inside the small shop, then asking for a way too high price to take me to my target (only asphalt). It still wasn’t expensive in the absolute sense and I want to reach the target as soon as possible, so I let it go without too much hassle. Ayrakty is the name of the rocky mountain I’m heading now

Except a small portion on the south, the horseshoe shaped structure is surrounded on all sides by vertical cliffs, making impossible to reach the flat plateau on the top from other directions

Stone umbrella, good shelter against the punishing sun. It’s around 4 PM, I’ve measured 38-39 degrees Celsius by hand (circling the cable with the sensor around at head level)

Inside the giant “U”, facing the concave dead-end. I’ve scanned with my eyes the cliffs, but couldn’t found a promising line where I could attempt to reach the top, even without the big luggage. Beside the steepness, the rock type is also bad (marl), which would make this plan very dangerous

The whitish towers protected me in the afternoon heat, I rested some time in the shade before continuing the hike

The elevation of this spot is pretty low, below 100 meters (but above the sea level), while the plateau abruptly rises 250-300 meters above the plain

Using the shade of the western “leg” I started to get around the structure, in the first part mostly on the same track from where I came

First glimpse of Sherkala, another inselberg, the most famous in Mangystau

That’s right, it seems that the only way up is a narrow strip on the southern sector where a little scrambling can take you to the top of the plateau

The rectangular slabs could be massagetae (ancient nomad horse people related to the scythians) pillars (?), similar rudimentary or a little more decorated structures can be found scattered around also on the neighboring Ustyurt plateau

The Zobject on the concave, but this time upper part of the huge horseshoe

The somewhat higher elevation makes the weather quite pleasant after sunset, also there are no mosquitos. Did I slept well? Nope, actually close to nothing. The wind intensified in the night, just when I was finishing to admire the Milky Way and trying to get some rest. The violent shake of the tent went till the dawn when I packed my things and continued the journey

The view to the east is spectacular, but I need to be careful not to go too close to the edge as with the big luggage on my back the wind is affecting my balance

Another mighty inselberg, has no name on the topo map

Continuing to follow the edges, this time on top of the eastern leg

I’ve already spotted them in the previous evening not too far from my camp. They must use the same steep slope to reach the plateau for grazing and descend to another location for water as here up is certainly nothing to drink

Sherkala (Lion’s castle) dominates the western horizon, I am heading right there

It is said that there is tunnel excavated during an old war, which leads to the top, otherwise it’s the same kind of inaccessible natural fortress like Ayrakty, if not even more

Remote farm not far from the asphalt road

There are some spherical concretions present in the area, a peculiar geomorphological phenomenon found also in my homeland, Romania (named “trovanți” there)

Far less in number than in the famous “valley of the balls” at Torysh (situated farther to the west near Tauchik), but without enough time to go there, I’m glad to see a few here

Around 9 AM I am at the iconic viewpoint towards the “yurt shaped” Sherkala. Meanwhile the wind didn’t gave up, but the sky remained clear

Hitchhiking from the nearby asphalt road a loud and at first quite rude “melon guy” picked me up, but the realization that we are exactly the same age was enough for him to became friendly and asking for selfies, then taking me to his spot in the bazaar of Shetpe. After drinking kumys (fermented mare milk) and eating I continued the hitchhike towards Aktau from the crossroads in the other side of the settlement. My new target is the beach named “km 43” (likely the distance from the city). I started by foot in the heat of the early afternoon (see picture above), but didn’t reached too far when some helpful youngsters picked me up

This area is relatively “crowded”, okay, I mean by kazakh standards. The locals (mostly from Aktau) come here to chill and take a bath. The coast is rocky, but not the “greek-type”, where you can jump directly from the shore. With variable depth, the water is tricky, with new obstacles still appearing after thinking you passed over them. Skal’naya tropa looks more rough because of its big boulders, but actually is easier to swim there

I rested more than the previous night on the windy plateau, probably helped also by the relaxing murmur of the waves. Most people don’t stay here overnight, they return home in the evening. The beach is reachable by car, but there are no facilities at all. As usual, the start is before sunrise, the temperature still warmish

The Tüpkaragan peninsula’s coast continues to the north-west towards Fort-Shevchenko, a small town with military-base

The landscape is fragmented only near the coast, the plateau is very flat with little to no landmarks

Looking towards Aktau from the southern ledge

This lizard is even more common than the camels, you can often spot them while sneaking away in the sparse, hardy grass

Reaching the main road at “km 43” I was questioned by a police patrol about my journey, but they not even checked my passport. I didn’t encounter any troubles relating the authorities during my travel and had the general feeling that the country is both safe and peaceful

The hitchhike to the city went smooth. People generally will expect to be paid for the ride, sometimes they will even tell you the price in the beginning. As the train is the backbone of the kazakh public transport (the bus services are scanty), the more remote settlements are harder to reach for tourists. The best option is probable to hire a car

WW2 memorial in Aktau. Life is not easy here, the economy struggles. The prices are low for western standards, a clear advantage for travelers

Here and there some more modern buildings break the general “soviet architecture” style of the city

MiG fighter plane monument with a characteristic “aktauish” block in the background

The statue of ukrainian poet Taras Shevchenko, who was exiled to the Mangyshlak in the 19. century. He is likely the most famous historical figure of the area as beside Fort-Shevchenko even Aktau’s previous name was also Shevchenko

Satisfied with the previous experience I returned to the same hotel. The staff was very operative and punctual, calling for taxi when I needed, explaining to the driver in advance my plan. Tomorrow I will go to collect the measuring equipment in the Karagiye Depression and I decided to reach the target from the other side of the basin, starting the hike in the south-west from the Kuryk road. It’s significantly farther from this direction and I will need to cross the salt pan situated at the very bottom

My favorite drink in Mangystau: kumys, fermented mare milk. You can buy it as you buy the beer in other countries. There are more variants, this particular one was the best: refreshingly sour, very fizzy (small bubbles), sufficiently sweet, with just a hint of alcohol (1-2 %). Also, very nutritive. However, you need to be very careful when opening to avoid the lurking disaster (personal experience…)

As the hotel sits close to the southern outlet of the city, the Kuryk road was simple to reach. The pranky azerbaijani driver (many taxi guys are from the Caucasus) took me to the chosen spot very fast, speeding close to 150 km/h on the good turkish asphalt. It barely passed 10 AM when I started the hike. After crossing (or trespassing?) the nearby railway’s (maybe only freight transport related to the ferry) barbed-wire, I maintained the north-east direction towards the depression

The weather in sunny, the heat somewhat less intense than during the first excursion. I have seven liters of water with me, as this time rested and hydrated myself well before in the hotel, compared to the rush with minimal preparation on 11th August. The progress on the flat plateau is easy, in about an hour I reach the ledge and have the first view of the salt pan

From the top I’ve observed a rather straight line which seems to go exactly in the same direction I’m heading to. A pretty long sector was composed of poles, maybe some fence in construction (or the opposite)

Already below -100 meters elevation. I’ve spotted some horses in the distance, which at first looked curious, then became kind of agitated. As I was heading towards them, they just waited watching me, then all at once run away sideways. But when I turned my head to the left to check them, I saw that all three were racing directly towards me!

However, when I raised the trekking pole and shouted once they instantly changed directions and run away to where they came

The camels have a more “phlegmatic” temperament, probably ideal in the heat where you need to be thrifty with your energy

It seems that this dirt road goes straight to the salt pan

-132 meters below sea level, the lowest spot of Kazakhstan and fifth in the world

The edge of the salt pan was slightly squashy, but afterwards the walk became comfortable on the hard surface

Somewhere in the middle of the white emptiness

There must be my target, I can discern the contours of the isolated sand pile in the distance

Not far from the other end of the salt flat the terrain became less solid again, moreover I started to sink ankle-height in the hot black mud. Yes, it was hot! I could feel through the shoes that it’s much warmer then my feet. There must be some thermal springs below, I don’t think the sun could heat it so much through the white crust.

Probably I got over it. The salt pan’s width was around 7-8 km

Still a little soft, but the danger is over

Reaching the already familiar sand island, after 4 PM I rested some time in the shade offered by its steep slope before continuing to the weather station

Of course, it’s here! I made around 29 km from the Kuryk road

I checked the results which were very close to my expectations. The maximum temperature exceeded by half a degree (40.6 C) the record of the first day (when I was present), both on 12th and 13th August. Today was “only” 36.4 degrees, while yesterday 36.0 degrees, the weakest maximum. The lowest temp by far (19.3 C) was registered this morning. I stopped the logger at 6:40 PM when the screen showed 33.9 degrees Celsius

Some parts of the basin’s bottom is represented by takyr (turkic for “playa”), the characteristic cracked, dry clay surface. Satisfied both with the trip and the research I will spend the night in the same spot, a little farther, next to the other sand pile

In the latter part of the afternoon I observed some convective rain clouds in the south, south-east, probably between the sea and the depression. The night was starry again, but without ET. Even the mosquitos were more lethargic now

Early morning start the next day, the weather is clear, the temperature pleasant. Following a dirt road at the foot of the hills – which seems to be the main access inside the basin – , this time I was passing through the greener area of the flatland, where a strong “chemical smell” (likely a mix of camel and bird excrement) hit me

Aha, I saw some small ponds on Google Earth. Looks romantic, smells like shit. Literally

Better here. Despite the many signs of recent activity, I haven’t spotted any camels, only birds

Just after sunrise, a little farther there was a scenic place with heavily eroded white rocks

The slender tower must be the biblical Lot’s wife, who was turned into a pillar of salt

I apologize, that story happened near the Dead Sea in Israel. Still below the sea level, though

This bug has some capacity which is bordering the skills of David Copperfield: every time I tried to take a photo of him from the front, he automatically adjusted his position to counteract it, like it was a magnetic repulsion

It looks that this is the easiest way to get out of the depression, pretty straightforward, without getting lost in the labyrinth of the badlands. Planned and managed well, I still have sufficient water to finish the trip without risking dehydration

A last steeper part and I’m up on the plateau, very close to the asphalt road. A local resident picked me up soon and before 10:30 AM I was already back in Aktau

Reaching the coast, I had the opportunity to wash my dirty shoes and trousers in the Caspian and the strong sun guaranteed the quick drying. The desert footwear was so badly hardened by the salt after the water evaporated, that it became completely useless, as – partly due to its shape – I couldn’t put them on again with all my strength and ambition. Thus, I had to use the city sneakers instead for the return part of the hike

The road towards Microdistrict 3, where my hotel was. In Aktau the addresses are described exclusively by numbers, as a trio composed of microdistrict, building and apartment. Though, I saw also street names on the sign-posts, those probably are newer establishments

Sandy beach not far from the eastern end of the rocky promenade

This warship announced his arrival with a huge explosion sound, which I concluded must have been a legit artillery shoot (see the cannon in the front), fortunately not towards the coast…

I was chilling about two hours on the beach at Skal’naya tropa, sitting on a sun-warmed boulder, cooling down in the water (this time a little warmer, 24 degrees) a few times. Very pleasant experience as everything ended well and I’m not even particularly tired

With enough freetime at disposal I was wandering in the city, eating at a nice restaurant before getting a taxi to the airport, where I’ve booked the last night of the voyage. There are many people working as “taxi drivers” as part-time job and they usually will ask for a smaller amount (about half-price), which was also my case

After resting a few hours in the comfortable, air-conditioned room, it came the time to leave. On the whole the journey in Mangystau was a great experience, the weather superb, everything went smooth. Likely not my last time here

As I had around 10 hours to wait for the plane change in Istanbul, I used the day to visit the famous old center of the metropolis. Well, a little in a rush as the new airport is ridiculously far away, having to take three (if you know what you’re doing) different metros to reach close enough. The most touristic part is insanely crowded (peak-season, also Friday), a huge contrast compared with the spacious streets of Aktau. Two completely different turkic worlds…

Karagiye depression: below sea level, above human body (3/3)

Interpretation of the logger’s graph (using LogTag Analyzer 3 software)

*The temperature curve of the 6 days/ 5 nights research period. The device was registering a value every 2 minutes (zoom in for better view)*

First day (August 11)

It is the single day when I’ve spent significant time nearby the measuring equipment. During the hike towards the bottom of the depression the sky was completely clear, the wind (easterly) light to moderate and these conditions continued also afterwards the entire day. The data logger started the continuous measurements at 12:42 PM, the first reading was 36.6 degrees Celsius. As I set the device for 2 minutes logging (short intervals) the curve has the typical “saw aspect” with many small ups and downs inside the general “big waves”.

Generally, the temperature was constantly rising until 4:48 PM, when the maximum of 40.1 degrees Celsius was reached. I was present, waiting in a camping chair at that time and observed little to no wind near the tripod in the hottest part of the afternoon. The obvious drop started after 7:30 PM and continued to 11:30 PM when the temperature reached 29.0 C. After that the curve became irregular, reaching the night’s minimum shortly before midnight (28.9 C), later climbing back to 31.6 C. As there were no clouds (I saw the starry sky through the transparent mesh of the mosquito tent), the disturbance was certainly caused by the wind. In the final part of the night, before leaving, I checked again the device and observed 29.9 C at 5:10 AM.

Second day (August 12)

The bulk of this day I’ve spent in Aktau after reaching the city around 11:30 AM, hitchhiking from the Zhanaözen road, north-east from the depression. The completely clear conditions continued, in the afternoon it was markedly hot even near the sea.

The graph shows a very regular diagram during the entire day, the temperature continuously climbed until it reached the maximum (40.6 degrees Celsius) at 3:32 PM, which is also the highest value of the entire measuring period. The earlier peak (maybe) could be attributed to the fact that the wind wasn’t dominantly easterly in the afternoon and the sea breeze could have slightly moderated the farther rise in the mid afternoon.

The obvious drop started again around 7:30 PM and lasted until 11:10 PM, when 28.7 C was reached. A very similar pattern with the previous day & night combo, complemented also with the following irregularity (certainly wind again). The main difference is that this time the minimum went down to 24.5 C in the early morning (5:52 AM).

Third day (August 13)

Today I left Aktau and travelled by train to Shetpe town, where I visited the inselberg named Ayrakty. I reached the area after 3 PM and saw no clouds in the sky during the entire day. In the afternoon I observed 38-39 C (hand measurement) around 70-80 m elevation. The wind was light until the evening (even on the elevated plateau), however in the night became consistently stronger. The sky remained clear.

Likely because the wind became again south-easterly, the maximum (40.6 degrees Celsius for the second time, equaling the previous record) was reached at 4:52 PM, very similar with the first day’s case. The obvious drop now started around 8 PM and except a short disturbance period between 10-11 PM continued pretty constant until the morning (7:02 AM), when reached the minimum of 26.3 C.

Fourth day (August 14)

Starting in the night, this day was a windy one and slightly less hot than the previous three, which were very alike. I hiked in the surroundings of Shetpe (Ayrakty and Sherkala) and observed almost no clouds. In the early afternoon I moved closer to Aktau to the so called “km 43” beach, where the sky became partly cloudy.

The day part of the graph looks quite regular again, reaching the maximum of 38.1 degrees Celsius at 3:50 and 3:58 PM. However, the obvious drop started much sooner this time (sea breeze?), around 5:45 PM and lasted until 9:10 PM, when reached 30.0 degrees. From here the curve is more irregular (I suspect wind again), but generally was descending until the morning, when reached 24.5 C at 6:54 AM.

Fifth day (August 15)

Sleeping on the beach, I continued the hike in the morning towards the road, where I hitchhiked back to Aktau before noon. It was mostly sunny with scattered altocumulus clouds in the city, the temperature less hot than before. The wind was much lighter than yesterday in the Sherkala area.

The daily graph looks normal again, reaching the peak of 36.0 degrees Celsius at 3:54 PM, which is the “weakest” maximum of the entire measuring period. The obvious drop started around 6:45 PM this time and was clean until around 10 PM, when reached 28.0 C. Then the descend became less regular with some abrupt ups and downs during the night, though the general tendency was evidently downwards. The minimum happened at 5:52 AM in the morning and was much lower than the previous ones: 19.3 degrees Celsius.

Sixth day (August 16)

Today I went back to collect the measuring equipment, this time starting the hike from the Kuryk road, situated on the other side of the depression (south-west). In the early afternoon I’ve crossed the entire salt pan transversely, before reaching the weather station. There were some scattered clouds, but overall much more sun than shade. I stopped the logger at 6:40 PM when the screen showed 33.9 degrees Celsius. In this later part of the afternoon I observed some convective rain clouds in the south, south-east, probably between the sea and the basin.

*The temperature curve of the sixth (last) day*

The graph of this day is also pretty regular, but can be discerned a little “rush” as the maximum of 36.4 degrees Celsius was reached sooner than usual: 3:06 PM. I attribute this fact again to the changing wind directions (namely the sea breeze), which started to counteract the afternoon heat.

The average maximum temperature of the six day measuring period is 38.6 C, while the average minimum of the related five nights is 24.7 C, giving a mean amplitude of 13.9 degrees Celsius. This combo is above the level of the hottest places of Europe for the month of July, closer to the Karakum desert in Turkmenistan or south-eastern Turkey around the Syrian border. Though this could not be considered a fixed generality as this summer was hotter on average in many places, especially in the mediterranean basin.

General conclusions

The sky is usually clear without significant differences between day and night.
The temperature rise during the daytime is typically constant and regular, reaching the maximum between 3 and 5 PM, sooner in the case with a stronger sea breeze effect.
The evening and the first part of the night is less windy with a more abrupt and fluid temperature drop than after midnight, when disturbances are characteristic.
The daily amplitude is medium (11-17 degrees), even slightly small for an arid environment during clear conditions, in part caused by the low elevation, where the thicker atmosphere can trap more heat during the night.
It’s a markedly hot area compared with its relatively high latitude (43 N), closer to the level of the subtropical deserts.

Comparison with the weather station of Aktau

Situated near the coast, Aktau receives the moderating effect of the Caspian Sea, thus the maximum temps are generally a few degrees lower than the ones registered farther inland during sunny weather. If we compare it (see the Ogimet chart below) with the values of my station in Karagiye, the average difference between the two is 4.4 degrees in favour of the depression. The biggest discrepancy (5.7 degrees) happened on 16th, while the smallest one (2.1 degrees) on 13th August.

This latter small difference was certainly caused by the easterly or south-easterly wind, which annihilated the sea breeze even near the coast, while on other days the city’s atmosphere was moderated by the cooler marine currents. As the low elevation of the depression gives an advantage of 1 degree against the level of Aktau, the measured 38.5 degrees would mean around 39.5 at -130 m, which is only one degree apart from the 40.6 degrees Celsius what I’ve recorded at my station.

The statistics of Aktau (Sevcenko) weather station for the 11-16th August period. Note: there is a one day positive shift as “consideration for the last 24 hours”, thus day 12 means day 11, while day 17 means day 16 (Ogimet)

Adding the 4.4 degree advantage to the average maximums of Aktau (see the Wikipedia chart) for the months of July and August will give 36.3, respectively 35.3 degrees Celsius average max for Karagiye, while adding the 2 degree difference (easterly dominance) to the 44 degree absolute maximum of the city will give around 46 degrees Celsius as a hypothetical heat record for the depression.

Addition: I’ve checked before the weather statistics of Aktau airport station on the Wunderground site’s history section (now unavailable) and saw that the maximums were 37, 37, 39 degrees Celsius (rounded values) for 11, 12, 13th August. As it is a little farther from the coast than the city, the somewhat higher peaks are understandable.

Comparison with Europe’s hottest areas

Regarding the extreme high temperatures, this summer was one of the most severe from the very start of the reliable meteorological measurements. The extensive heat domes affected the mediterranean area both in July and August during more successions, climbing the mercury of the thermometers to record or near record levels in many places. The most affected areas were the North African coast (Algeria, Tunisia), respectively Sardinia island and southern Spain where the temperature raised to 45-49 degrees Celsius.

*The maximum temperatures recorded on 12th August in Europe (Ogimet)*

This amount of heat is about 10-15 degrees above the average summer maximums of the mentioned areas, concretely at the level of Death Valley or of the Iran-Iraq-Kuweit triple border region, which are the hottest places of the Planet. Taking this into account it can’t be made a conclusive comparison between my study area and Southern Europe in the actual situation. Regarding the broader summer max averages Karagiye is probably alike the hottest areas of Andalusia (thus of entire Europe), which is around 35-37 degrees in July and August, while the absolute record potential could be between 46-48 degrees Celsius, also similar.

Altogether, for a “substitute plan” the research went quite well, both the conditions and the results can be considered decent for the context.

Jargalantyn Mukhar: the driest cold (3/3)

Interpretation of the logger’s graph (using LogTag Analyzer 3 software)

*The temperature curve of the 6 nights/ 5 days research period. The device was registering a value every 5 minutes (zoom in for better view)*

First night (14th January)

I installed the measuring equipment on the bottom of the closed basin in the second part of the night during clear and calm conditions. The logger set for 5 minutes intervals was started at 2:26 AM and the first reading showed -32.5 degrees Celsius. The second value is -33.2 C, which remains constant for the next 20 minutes, so its possible that the debut temperature actually was the same. I left the tripod around 2:40 AM and returned there in the early morning. During my walk from the tent situated aproximatively 2.5 km to the south I measured in the col between -26, -27 degrees with the handheld device, noticing also some wind there. The night remained entirely clear and on the bottom were the same calm conditions as at the time of the installation.

The temperature curve of the first (half) night and the following day

However, the temperature wasn’t lower in the dawn than before, the device showing -32.5 degrees at the first check. The recorded minimum was -34.1 degrees Celsius, which happened at 5:31 and 5:36 AM. A pretty constant night curve. But there are two more interesting aspects, one is the weak thermal inversion related to the context, which is around 6, maybe 7 degrees compared with the col, the other the complete lack of hoarfrost, which denote an extremely low humidity. I left the basin after sunrise. The entire day remained cloudless with only weak wind even on the ridges. The maximum, which I saw after returning in the next morning reached -16.3 degrees Celsius at 2:56 PM. That means a pretty big amplitude (17.8 degrees), which was expectable for a high altitude basin.

Second night (14-15th January)

The dark hours were completely starry again, but the wind intensified in the latter part of the night. Before the instability I measured down to -27 degrees inside my tent, expecting to see an even colder recorded minimum in the endorheic basin. It wasn’t the case, the lowest achieved temperature being only -33.6 degrees Celsius (at 5:21 and 5:26 AM), half degree warmer than before. As these two nights represents characteristic anticyclonic conditions I think that a generalization regarding the relatively weak thermal inversion of this place in snow-free context is very plausible.

*The temperature curve of the second night and the following day*

While there before sunrise I observed the first cirrus clouds coming from the west. I left the basin soon and around noon also my camp. The day was generally fine but ocasionally windier, the sky partially covered by cirrus and cirrostratus clouds, with some thickening in the late afternoon period. I was spending my time around 10 km to the south of the research area staying in yurt with locals. The maximum of this day reached -13.1 C at 2:06 PM, which combined with the minimum of the dawn gives an amplitude of 20.5 degrees.

Third night (15-16th January)

From now on I will not visit the studied spot until the final day when I will collect the equipment, but will remain in its neighborhood (no more than 15 km away) most of the time. In the morning I measured -20.7 degrees with the handheld device at the yurt. The sky was mostly cloudy, overcast or variable with intensifying wind in the early afternoon when there were some very weak snow showers here and there, covering some parts with a new veil with a thickness of a few millimeters. In the latter part of the day the sky cleared up.

*The temperature curve of the third night and the following day*

The diagram confirms the unstable weathern pattern, the curve being less regular and showing a smaller amplitude. The minimum reached -25.6 degrees Celsius at 9:25 AM, while the maximum -18.2 at 1:36 PM, the latter actually being colder than the late evening hours of the previous day. The 7.4 degree amplitude is the weakest one in the entire research period.

Fourth night (16-17th January)

While fair in the first part, the sky became overcast during the night. The curve reflects this as the minimum of -31.5 degrees Celsius was reached already in the late evening at 11:16 PM. In the morning I measured -20.8 degrees at the yurt, while observing a cloudy sky. The mostly overcast conditions persisted throughout the day in the whole area, including Ulaantolgoy where we made a trip with the car. Generally it was moderately windy.

*The temperature curve of the fourth night and the following day*

The maximum reached -10.9 degrees Celsius at 1:56 PM, which is the highest temperature of the entire research. The daily amplitude of 20.6 degrees is also the biggest one, slightly exceeding the one from 15th. However, this can’t be considered a real endogen thermal span like the ones forming during stable weather conditions.

Fifth night (17-18th January)

This night was the windiest, more precisely the second part when I observed the yurt’s rooftop shaking a little at a certain time. In the morning the sky was clear, but because of the instability the temperature was even less cold than in the previous two cloudy days: -19.4 degrees. The minimum was reached again in the first part of the dark hours: -27.5 degrees Celsius at 11:21 PM when the conditions were more stable, while afterwards the temperature rised 10 full degrees during the second part of the night when the wind became dominant.

*The temperature curve of the fifth night and the following day*

The maximum happened at 2:16 PM when the temperature climbed to -12.2 degrees, the second highest peak of the research. Today the sky was strikingly bright, even more transparent than on 14th, with only a few isolated clouds lingering above the higher peaks on the distance. It remained moderately windy throughout the day. The 15.3 degree amplitude can be considered average.

Sixth (last) night (18-19th January)

This was the coldest night by far at the yurt. The sky remained starry and there was nothing more than light wind. In the morning I measured -26.8 degrees. This time I observed also hoarfrost on the surface, thus the humidity was higher than before. I expected again to found a lower temperature in the closed basin (at least -33 to be precise), but surprisingly the minimum didn’t went below -31 degrees Celsius there, reinforcing my previous conclusion regarding the weak thermal inversion of this high elevation + snow-free combination.

*The temperature curve of the sixth (last) night*

The low temp was reached at 7:21 and 7:26 AM in the morning after a relatively regular night curve with some mild to moderate disturbance between 1 AM and 4 AM. Leaving the yurt, as we started our way back to Khovd, I went to collect the measuring equipment. The logger was stopped at 10:18 AM, the last reading showing -25.4 degrees Celsius. During this period it was calm and the sky was partially covered with cirrus and cirrostratus clouds.

The mean temperature of the 6 nights/ 5 days research period is -22.5 degrees Celsius, with the average minimum -30.6, respectively the maximum -14.1 degrees. The average daily amplitude is 16.3 degrees.

General conclusions

The elevated basins situated on the lee side of the Mongolian Altai’s main ridge are characterized by very dry winters, receiving scant amounts of snowfall, often remaining without snow cover for the biggest part of the cold season. The stronger solar radiation and more active wind also helps to maintain the already desiccated state, sublimating the thin layer of white powder. This combined with the seasonally dominant anticyclonic conditions make these places some of the best contestants to produce the lowest temperatures in snow-free context.
The thermal inversion formed at the bottom of these bare basins are not really strong, the surrounding ridges and slopes cooling down to almost the same degree during the night. The main cause in this respect probably is the absence of the snow cover and not the elevation itself, also maybe because the plateau as a whole could be partially inside the inversion layer.
Compared with similar topographical contexts situated at lower elevations the daily maximums are higher (the inversion here brakes completely), while the minimums can be close to each other.
The air is very dry on the high plateau, sometimes also in the night, restraining the formation of the hoarfrost even at extremely low temperatures.
The wind in the wintertime is generally not strong.

Satellite image taken on 14th January 2023 showing the marked snow-cover discrepancy between the outer and inner sides of the Mongolian Altai with Jargalantyn Mukhar basin inside the red ellipse

Comparing my logger’s results with the minimums registered at the official local stations situated also in generally snowfree areas

During my staying I visited the weather stations of Möst, Mönkhkhairkhan and Khovd where I asked about the parameters observed in these colder winter days. On 14th Khovd (Khovd aimag/ 1406 m) and Ömnögobi (Uvs aimag/ 1590 m) both recorded -28.7 C, the latter -31.2 C the day before, while Nogoonnuur (Bayan Ölgiy aimag/ 1480 m) -26.2 C, respectively -30.8 C on 13th. Möst (Khovd aimag/ 2020 m) reached -30.1 C on 14th and was slightly warmer both on 13th and 15th, while Mönkhkhairkhan (Khovd aimag/ 2090 m) was colder on 13th with -30.3, while having only -28 on 14th.

The coldest station which reported no snow cover at that time was Tsetsegnuur (Khovd aimag/ 1715 m) situated in a closed intermountain basin near the lake with the same name: -34.4 degrees Celsius on 14th January. This is even slightly colder than the value registered by my station. However, I checked the satellite image of the Tsetseg basin for that day (lower-right corner of the above image) and saw that actually there is a thin layer of snow in most parts. This doesn’t mean they gave incorrect data as the stations are obliged to report the snow depth they see at the rulers placed on the weather platform. The snow often can disappear sooner there, while in the surroundings still remains some.

At the weather center in Ulaanbaatar I asked if they have some statistics regarding the lowest temperature measured in snow-free conditions. They didn’t have, but together we searched for Tsetseg specifically and found a minimum of -36 degrees on 23th January 2012. At home I checked the satellite image also for this day and the result was similar: the basin wasn’t completely bare (see the picture below).

This image has an empty alt attribute; its file name is Tsetseg_Eosdis-1024x675.jpg — *Satellite image showing the snow cover situation in the Tsetseg basin on 23th January 2012 with the location of the weather station (red dot)*

As a conclusion I would say that between the official weather stations of Mongolia indeed Tsetsegnuur has the biggest chances to reach the lowest temperatures. This because of the combination between the good topography (high+closed), respectively the rain shadow effect caused by the Mongol Altai’s main ridge which blocks the humid airmasses on the other side. The same as in the case of Jargalantyn Mukhar.

Final question: How cold can get in snow-free context and exactly where in the world are the best chances for this to happen? My opinion is that some areas of Mongolia and the northern part of the Tibetan Plateau could reach even slightly lower than -40 degrees in the best circumstances. As I am determined to research this little studied domain farther, the future certainly still has many other thrillful things to offer.