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.

On the way to the target

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…

Leave a Reply

Your email address will not be published. Required fields are marked *