VARIATIONS AND TRENDS IN ANNUAL MEAN AIR TEMPERATURES IN TURKEY WITH RESPECT TO CLIMATIC VARIABILITY

The purpose of this study is to investigate the variations and trends in the long-term annual mean air temperatures by using graphical and s tatistical time-series methods. The study covers a 63-year period star ting from 1930 and uses temperature records from 85 climate stations. First, spatial distributions of the annual mean temperatures and coeff icients of variation are studied in order to show normal conditions of the long-term annual mean temperatures. Then variations and trends ob served in the annual mean temperatures are investigated using temperat ure data from 71 climate stations and regional mean series. Various no n-parametric tests are used to detect abrupt changes and trends in the long-term mean temperatures of both geographical regions within Turke y and individual stations. The analyses indicate some noticeable varia tions and significant trends in the long-term annual mean temperatures . Among the geographical regions, only Eastern Anatolia appears to sho w similar behaviour to the global warming trends, except in the last 5 years. All the coastal regions, however, are characterized by cooling trends in the last two decades. Considering the results of the statis tical tests applied to the 71 individual stations data, it could be co ncluded that annual mean temperatures are generally dominated by a coo ling tendency in Turkey. The coldest years of the temperature records of the majority of the stations were 1933 and 1992, respectively.