Past and Furture

Climate Comparison: Istanbul, Turkey and Buenos Aires, Argentina

For an interesting climate comparison I tried to find a location with similar latitudes but in opposite hemispheres. Buenos Aires seemed like the best because it is also near the coast and shares similar characteristics.

(Map of Buenos Aires and Istanbul, Source: Google Maps)

For the Köppen Geiger Classification both Buenos Aires and Istanbul have a C, or Mediterranean, climate. This makes sense because both are in the midlatitudes and near water. However, Istanbul is a Csa classification and Buenos Aires is Cfa. Both share the same temperature rating: "a" for the hot summers but they differ in precipitation. Istanbul has the "s" for dry summers where Buenos Aires has an "f" rating for fully humid. This can be attributed to the fact that Buenos Aires is slightly closer to the equator and that means different air mass circulation.

(Air masses and circulation patterns, source: Islandnet.com)

The image above shows the air circulation and patterns around the globe. This shows the source of Buenos Aires' copious precipitation and Istanbul's drier climate. Although they are close to the same latitudes, Buenos Aires is on the eastern side of the South American continent and there is a Maritime Tropical air mass right off the coast the circulates counter clockwise (Because it's in the Southern Hemisphere) and that brings all that moist ocean air right to the region. On the other hand, when you look at Istanbul you see that it is still getting Tropical air but it's Continental Tropical because it has been circulating over Africa. Also, because Istanbul is in the Northern Hemisphere the air circulates in the opposite direction: clockwise over the Mediterranean Sea.

(Another view of differing air masses, source: rst.dsf.nasa.gov)

Information Sources:

Climates and Climatology Lecture, Fred Chambers, GEOG 3232

http://buenosaires-dylanlewan.blogspot.com/

Past, Present, and Future of Istanbul, Turkey

Istanbul, Turkey has been on a wild ride as far as tectonics are concerned. Its journey has taken it from completely submerged underwater to tropical paradise, from Mediterranean to high mountaintops. This roller coaster is a doozy but it all goes to show the power behind our changing planet.

Present

(Current World Map, Source: lib.utexas.edu)

In order to effectively compare Turkey of the past with Turkey of the future a base line should be clearly defined. That means just a little recap of modern Turkey and its characteristics. Turkey is located in between the Mediterranean Sea and the Black Sea at about 39˚N and 35˚E. It is classified as having a mostly Mediterranean climate with hot, dry summers and mild, wet winters. Current air masses that affect this area include the Asian High and several Mediterranean Lows. Because of the midlevel latitudes, Turkey has fairly variable weather throughout the year. There are very distinct seasons but nothing too extreme.

(Climograph for current day Istanbul, Source: istanbul.climatetemp.info)

There is moderate variation in temperature and precipitation, thanks to its latitude and regional air masses.


100 Million Years in the Past

(Earth 100 million years ago, Source: ncdc.noaa.gov)

In the not so distant geologic past, 100 million years or so, Turkey was under water. This could be because the ice caps were holding less water and the oceans were at higher levels. It was also about 10˚ closer to the equator in latitude because of tectonic forces. Both of these factors have major impacts on the region’s weather and climate. Because the country is underwater, I will just focus on the land nearby and the area as a whole. Much like where it is now, the region is centered on a small sea. This one was a little bigger than the Mediterranean Sea, near where Istanbul is now. I think in the past Istanbul was a fair comparison with Muscat, Oman. Muscat is on the coast of the Indian Sea and at around 30˚ latitude, much like 100 million-year-old Turkey. Using that comparison I would expect old Turkey to be a very turbulent place being so close to the ITCZ and large bodies of water. I would also expect a climograph to be very similar to the one below.

(Modified climograph of Muscat, Oman to represent Turkey 100 million years ago, Source: climatetemp.info)

I think this is a good representation of old Turkey because it shows the less variable, warmer temperatures, as the region was much closer to the equator. This would lead to higher levels of insolation and the area would absorb more solar energy. For Turkey itself, being underwater and all, it would retain a lot of that energy because water heats and cools slower than land. This process also explains the little variation in temperatures.

100 Million Years in the Future

(Estimated map of Earth 150 million years in the future, Source: scotese.com)

As the tectonic plates continue to shift and move Africa was smash into where Turkey currently resides. As it pushing up into Europe the Mediterranean Mountains will be formed and Turkey will sit right on top. Also, the whole region will move farther north. Having always been near water, this new location will drastically alter Turkey’s weather and climate. It will find itself land locked and, for the first time, dealing with continentality. Also, the higher latitude will greatly change the current air masses affecting the area.

(Modified climograph for Moscow, Russia to represent Turkey 100 year in the future, Source: climatetemp.info)

This modified climograph of Moscow, Russia serves as a fairly good estimation for the weather and climate of new Turkey. Like Moscow, Turkey will be a landlocked subarctic region with very high temperature variation throughout the year and fairly low precipitation. However, unlike Moscow, new Turkey will have a very high elevation that may cause greater precipitation but if I were to guess I would predict a good majority of Turkey would be covered in new glaciers, as the pattern of melt/thaw continues. Of course, in order for glaciers to develop snow must fall.

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

Air Masses and Moisture

Istanbul's unique location leads to high amounts of precipitation. Its aquatic neighbors, the Black Sea and the Sea of Marmara, are huge providers or moisture and rain. However, it takes more than just nearby bodies of water to cause clouds and rain. The Atacama Desert is the driest place on earth and it directly on the coast of the Pacific Ocean. Along with a source of water you also need the movement of air and circulation. The image below shows the path of the solar eclipse of this past March, Turkey in red, but more importantly it clearly shows the air patterns common in this area. The Siberian Anticyclone is known to develop over Asia and circulates air past the Black Sea on its way to Turkey, bringing moist air onto land.

(Path of the March solar eclipse with Turkey in red - Source: http://eclipse.gsfc.nasa.gov)

Aiding in this movement are the several Mediterranean Lows. According to NASA there are a number of locations in the Mediterranean area that a common “sinks” of low-pressure systems. One of which just so happens to reside directly over Istanbul. This system usually develops in the string months but can be seen all year. It is this combination of the Siberian High, Mediterranean Lows, and the two seas that drives Istanbul’s weather and precipitation.

(Climate Classification for Turkey - Source: www.atc-anadolu.com)

The map above shows Istanbul classified as having a “humid” climate. Knowing its location and air patterns this seems perfectly reasonable.

(Precipitation for Turkey (mm) - Source: www.atc-anadolu.com)

Sources:

http://eclipse.gsfc.nasa.gov/SEpubs/20060329/text/section2.html

www.britannica.com/EBchecked/topic/372680/Mediterranean-low