Trends in surface air temperature data over Turkey

Eighteen stations are considered for the study of climatic records over Turkey in search for possible trends. Mean, unfiltered, seasonal and annual maximum and minimum temperatures are analysed using the Mann-Kendall rank statistic to demonstrate any existence of possible trends. The analyses indicate that the mean annual temperature records in Turkey have a warming trend over the 1939 to 1989 period, but a cooling trend from 1955 to 1989. These trends in mean annual temperatures, however, are not statistically significant. Comparatively greater warming effects have occured in spring and winter minimum rather than the maximum temperrature records. A regional increase in the mean minimum temperature around 1955 is attributed to the urban heat island effect. In general, general circulation models (GCM) predictions are consistent with the sign of the trends only in Turkish climate records during the entire 1939 to 1989 period