Re-evaluation of trends and changes in mean, maximum and minimum temperatures of Turkey for the period 1929-1999

Mean, maximum and minimum surface air temperatures recorded at 70 climatological stations in Turkey during the period from 1929 to 1999 were analysed to reveal spatial and temporal patterns of long-term trends, change points, significant warming (cooling) periods and linear trend rates per decade. Annual, winter and spring mean temperatures have tended to increase, particularly over the southern regions of Turkey, whereas summer and particularly autumn mean temperatures have decreased over the northern and continental inner regions. Annual, winter, spring and summer maximum temperatures have indicated a positive trend at many stations, except those in the Central Anatolia and Black Sea regions and partly in the Eastern Anatolia region. Autumn maximum temperatures, however, have decreased slightly over much of Turkey, except for the Aegean region. The majority of the urbanized and rapidly urbanizing stations in Turkey have been experiencing an apparent night-time warming, especially during the warm and dry period of the year. Minimum temperatures have shown a statistically significant positive trend at 31 stations annually, 30 stations in spring and 33 stations in summer; most are significant at the 0.01 level. Winter and autumn minimum temperatures have indicated a general negative trend in some portions of the Marmara, Black Sea and Eastern Anatolia regions, Whereas a general positive trend has been seen over much of Turkey along with the significant trends in the Mediterranean region of the country. Summer night-time warming rates are generally larger than in spring and autumn night-time temperatures. On the other hand, the night-time warming rates of spring and summer are generally stronger than those in spring and summer daytime temperatures. By considering the marked increasing trends in spring, summer and annual minimum temperatures of urban stations, we have recognized that this is a clear and significant indication for the existence of a strong night-time urban warming in Turkey. Copyright (C) 2002 Royal Meteorological Society.