On the Flood Forecasting at the Bulgarian Part Of

BALWOIS 2004 Ohrid, FY Republic of Macedonia, 25-29 May 2004 The Mountains Influence On Turkey Climate Serhat Sensoy Turkish State Meteorological Service Ankara, Turkey Abstract Since the Black sea mountains at the north of the country and the Taurus mountains in the south lay parallel to the seashore and rise very sharply, rain clouds can not penetrate to the internal part of the country. Rain clouds drops most of their water on the slopes opposite the sea. As rain clouds pass over the mountains and reach Central Anatolia they have no significant capability of rain. For this reason, the Central Anatolia does not have very much precipitation. The difference between the rates of precipitation on the inner and outer slopes seems to be effective on the expansion of plants. Since the succession of the mountains in Western Anatolia lay perpendicular to the seashore, rain clouds penetrate towards the inner regions for about 400 km. Owing to the irregularity of its topography, various types of climate ranging from subtropical to cold climates characterize climate in Turkey. Key words. Mountain, effect, climate, Turkey, rainfall, intensity, analyze What is climatology? Climate is what you expect. Weather is what you get. Weather is the state of the atmosphere, over a brief period of time. For example, we speak of today's weather or the weather this week. Climate represents composite of day-to-day weather over a longer period of time (NDMC, 2004). In other word, climate is the average state of the atmosphere. Climate can be highly variable. For example; people in Mediterranean expect a white Christmas, and people in East Anatolia expect very warm, humid summers. It is no coincidence that we pack differently when we travel in March to Uludag, Antalya or to Trabzon. These examples begin to show how we use climate to live our lives. Additionally: (a) Our houses are designed based on the climate where we live. (b) Farmers make their plans based on the length of the growing season from the last killing freeze in the spring to the first freeze in the fall. (c) Utility companies base power supplies on what they expect to be the maximum need for heating in the winter and the maximum need for cooling in the summer. A climatologist attempts to discover and explain the impacts of climate so that society can plan its activities, design its buildings and infrastructure, and anticipate the effects of adverse conditions. Although climate is not weather, it is defined by the same terms such as temperature, precipitation, wind, and solar radiation. Climate is usually defined by what is expected or "normal," which climatologists traditionally interpret as the 30-year mean. By itself, "normal" can be misleading unless we also understand the concept of variability. For example, many people consider sunny, days as normal in Antakya. History and climatology tell us that this is not the full story. While sunny weather is frequently associated with Antakya, severe floods also have had a significant impact, including major floods in 1941 and 2001. If we know the status of the climate today and the differences between this and the recent past, we can begin to plan for the future. (Obasi, 2001) Major air masses that affect climate of turkey There are two types of air masses affecting Turkey; Polar and Tropical. They are also subdivided into two groups maritime and continental. Turkey is under the effect of polar air masses in the winter and tropical air masses in the summer. It is seen from Fig. 1. (a) Maritime Polar Air Mass (mP): It’s originated from Atlantic Ocean and passes over Europe. It brings rainfall to the Black Sea Region and snow to the inland regions. If it comes from over Mediterranean it became more effective. Climate 1 BALWOIS 2004 Ohrid, FY Republic of Macedonia, 25-29 May 2004 (b) Continental Polar Air Masses (cP): It’s originated from Russia and Siberian. It is cold and dry air masses and characterized by fog and clear sky at nights. When it passes over Black Sea, it picks moisture and can cause orographic rainfall in the Black Sea costal region. (c) Maritime Tropical Air Mass (mT): It’s warm and humid. This air mass forms over Azores Islands. It brings a lot of precipitation especially to the western part of Turkey in the summer. These two air masses control Turkey’s annual precipitation; and in the long-term, the control the variation of rainfall in duration and area rainfall distribution. (d) Continental Tropical Air Masses (cT): It’s hot and dry. It is originated from North African Desert. When it meets northern systems or picks sufficient moisture over Mediterranean, it can cause rainfall. Figure 1. Air masses affecting Turkey Turkey's climate is influenced from Northeast Atlantic Depression (low Pressure) and Subtropical anticyclones (Azorean high pressures), as well as the seasonal movement of Basra low pressure. In some years, especially in the winter season, Siberian anticyclone carries temporal polar air masses from the Russian plateaus to Turkey. There are four-pressure systems that affecting climate of Turkey: (a) Atlantic (Iceland) depression (Low Pressure) (b) Siberian Anticyclone (High Pressure) (c) Azorean Anticyclone (High Pressure) (d) Basra (Gulf) Low Pressure (extension of the monsoon low pressure) These pressure systems usually are stable, but sometimes they are affecting air masses over Turkey by expanding and narrowing. Climate of Turkey Although Turkey is situated in large Mediterranean geographical location where climatic conditions are quite temperate, diverse nature of the landscape, and the existence in particular of the mountains that run parallel to the coasts, result in significant differences in climatic conditions from one region to the other. While the coastal areas enjoy milder climates, the inland Anatolian plateau experiences extremes of hot summers and cold winters with limited rainfall. The Aegean and Mediterranean coasts have cool, rainy winters and hot, moderately dry summers. Annual precipitation in those areas varies from 580 to 1,300 millimeters, depending on location. The Climate 2 BALWOIS 2004 Ohrid, FY Republic of Macedonia, 25-29 May 2004 Black Sea coast receives the greatest amount of rainfall. The eastern part of the region receives 2,200 millimeters annually and is the only region of Turkey that receives rainfall throughout the year. Turkey's diverse regions have different climates because of irregular topography. Taurus Mountains is close to the coast and rain clouds cannot penetrate to the interior part of the country. Rain clouds drops most of their water on the coastal area. As rain clouds pass over the mountains and reach central Anatolia they have no significant capability to produce rainfall. In the Eastern region of Anatolia, the elevation of mountains exceeds 2500-3000 m. Northern Black Sea Mountains and Caucasian Mountain hold the rain clouds, and therefore the area is affected by the continental climate with long and very cold winter. Minimum temperatures of -30oC to -38oC are observed in the mountainous areas in the east, and snow may lie on the ground 120 days of the year. Winters are bitterly cold with frequent, heavy snowfall. Villages in the region remain isolated for several days during winter storms. Summers are hot and dry, with temperatures above 30oC. Spring and autumn are generally mild, but during both seasons sudden hot and cold spells frequently occur in the region Annual precipitation averages about 500-800 mm. with actual amounts determined by elevation. In Istanbul and around the Sea of Marmora the climate is moderate (winter 4oC and summer 27oC); in winter, however, the temperatures can drop below zero. In Western Anatolia, there is a mild Mediterranean climate with average temperatures of 9oC in winter and 29oC in summer. On the southern coast of Anatolia the similar climatic condition are observed. The climate of the Anatolian Plateau is a steppe climate. There is a great temperature difference between day and night. Rainfall is low but it usually is in form of snow. The average temperature is 23oC in summer and -2oC in winter. The climate in the Black Sea area is wet, and humid (summer 23oC, winter 7oC). In Eastern Anatolia and South-Eastern Anatolia there is a long winter, and snow remains on the ground from November until the end of April (the average temperature in winter is -13oC and in summer 17oC). Analysis of temperature Long term mean temperature of Turkey The lowest temperatures occur in the Eastern Anatolian (Ardahan) and highest temperatures occur in the Southeastern Anatolian region because of higher elevation and terrestrial climate. Most part of the central Anatolia has temperature between 8-12oC. In all part of the Marmora, coastal area of Black Sea, central part of the Aegean Sea and inland of the Mediterranean, the long-term annual mean temperatures are between 12-16oC. In the Aegean and Mediterranean coastal area and all part of the southeast Anatolia regions, the annual mean temperatures vary from 16 to 20oC. Geographically distributions of mean annual temperatures are seen in Fig. 2 and average air temperatures for major cities are given in Table 1. Figure 2. Geographical distributions of mean annual temperatures Climate 3 BALWOIS 2004 Ohrid, FY Republic of Macedonia, 25-29 May 2004 Table 1. Average air temperatures for major cities in Turkey (oC) City Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Antalya 10 11 13 16 20 25 28 28 25 20 15 12 Izmir 9 10 11 16 20 25 28 27 23 18 15 10 Istanbul 5 6 7 12 16 21 23 23 20 16 12 8 Trabzon 6 6 7 11 15 20 22 22 19 15 12 9 Ankara 0 1 5 11 16 20 23 23 18 13 8 2 Erzurum -9 -7 -3 5 11 15 20 20 15 9 2 -5 Diyarbakir 2 2 2 14 19 26 31 31 25 17 10 4 Temperature anomalies Long-term mean temperature of Turkey is 13.2oC.

Load more