Variations and trends in annual mean air temperatures in Turkey with respect to climatic variability

Abstract The purpose of this study is to investigate the variations and trends in the long‐term annual mean air temperatures by using graphical and statistical time‐series methods. The study covers a 63‐year period starting from 1930 and uses temperature records from 85 climate stations. First, spatial distributions of the annual mean temperatures and coefficients of variation are studied in order to show normal conditions of the long‐term annual mean temperatures. Then variations and trends observed in the annual mean temperatures are investigated using temperature data from 71 climate stations and regional mean series. Various non‐parametric tests are used to detect abrupt changes and trends in the long‐term mean temperatures of both geographical regions within Turkey and individual stations. The analyses indicate some noticeable variations and significant trends in the long‐term annual mean temperatures. Among the geographical regions, only Eastern Anatolia appears to show 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 statistical tests applied to the 71 individual stations data, it could be concluded that annual mean temperatures are generally dominated by a cooling tendency in Turkey. The coldest years of the temperature records of the majority of the stations were 1933 and 1992, respectively.