Climatology

According to the Köppen-Geiger Climate Classification Istanbul has a Csa climate. This means it has a warm temperate mediterranean climate with dry, warm summers and moderate, wet winters. The majority of Turkey shares this climate type with only the high mountains and plateaus having colder climates.

(Climates of Europe - Source: killacan.com)

As it has been stated before, water plays a critical role in the weather and climate of Istanbul. The city sits on two large bodies of water: the Black Sea and the Sea of Marmara. These seas obviously affect the precipitation of the region by supplying copious amounts of moisture in the air. But they also influence the temperature in the area because, as we all know, water heats and cools slower than land. This leads to a smaller temperature variance in the area and is a major reason why Istanbul enjoys such a temperate climate.

(Water front in Istanbul - Source: blacktomato.co.uk)

When looking at the history of Turkey as a whole there has been a general rise in average temperature. From 1971 to 2000 there was an overall rise of +0.64˚/100 year trend. There was a lot of fluctuation, as can be expected, but with a general increasing pattern.

(Temperature trend in Turkey - Source: Saylan, 2007)

There has also been a decrease in average precipitation and this is a major concern for the agriculture. Turkey is known for a number of cash crops like wheat, barley, cotton, and tobacco. These crops need a lot of moisture, particularly cotton and tobacco, and lower rain levels have been causing a number of problems. What is interesting is that while rainfall is decreasing there have been reports of higher evaporation. This could mean that increased solar radiation is causing water to evaporate but then that moist air is moving elsewhere so Turkey is drying out. This has lead to a very high demand for irrigation and the government has been heading several research projects to help maintain Turkey's ability to compete in the agricultural market. Some of these include ground water monitoring and water optimization through agricultural engineering.

(Wheat Field in Cappadocia, Turkey - Source: turkey-in-photos.com)

Sources:

http://www.weatheronline.co.uk/reports/climate/Turkey.htm

POTENTIAL IMPACTS OF CLIMATE CHANGE ON AGRICULTURE IN TURKEY by Levent Saylan, PhD.

CLIMATOLOGICAL APPLICATIONS IN TURKEY by Serhat Sensoy

Istanbul, Turkey vs. Shanghai, China

Istanbul, Turkey and Shanghai, China offer an interesting comparison in that they share similar latitudes and access to water but vary in other characteristics that drive each city’s unique weather patterns and climate.

Map of Asia with Istanbul and Shanghai highlighted

Source: Google Images

For one, Istanbul sits at about 288 m (945 ft) where Shanghai, built on an alluvial fan, has a measly 5 m (13 ft). As we have learned in class, elevation is a major factor of weather, as air cools as it rises. This means that the air in Istanbul is, on average, colder than the air in Shanghai. This impacts how much moisture air-masses can carry over these areas, as well as dew point levels and other precipitation elements.

Siberian High Pressure System with Both cities highlighted.

Source: atmos.umd.edu

Another interesting comparison is that the weather of both cities is actually influenced by the same semi-permanent high-pressure system that develops over Asia, only in different ways. The Siberian Anti-Cyclone (Or Continental Asian High) rotates clockwise over mainland Asia, bringing rain to Istanbul and the dry season for Shanghai. The easterly winds from the lower-left part of the system blows air across the Black Sea into Istanbul, causing that area’s wet season. By the time the system travels across all of Asia and gets to Shanghai, on the other side of the high, the northwesterly winds have been drained of their moisture. So while both cites are affected by the same system they experience entirely different conditions.

Climate Graph for Istanbul

Source: istanbul.climatetemp.info

Climate Graph for Shanghai

Source: shanghai.climatetemp.info

Of course, this pressure system is not year round and during its absence the weather in both cities swap. As stated in the last blog, when the high is over mainland Asia a number of low systems develop around Istanbul, thus all the rain. When the Asian high dissipates so do the lows over Istanbul and the weather mellows and becomes more temperate. However, in Shanghai, when the high moves out lows move in and their monsoon season begins. Looking at the two graphs above you can see how the wet season in Shanghai follows almost immediately after the rainy season in Istanbul and that the relative humidity of both cities are inverted.

Sources:

http://shanghiweatherandclimate.blogspot.com/

http://en.wikipedia.org/wiki/Istanbul

http://www.chinahighlights.com/shanghai/shanghai-facts.htm