Temperature trends and changes in Rize, Turkey, for the period 1975 to 2007

Abstract

There is increasing evidence that the global climate is changing as a result of anthropogenic activity. Short-term mean, maximum, and minimum temperatures of the city Rize located at the Eastern Black Sea Coast of Turkey were analyzed to reveal trends, change points, significant warming (cooling) periods, and trend rates per year. An increasing trend of approximately 1.27 degrees C/33 years (alpha = 0.001) in the annual mean temperatures is found during the period from 1975 to 2007. Two periods, averaging 13.78 and 14.66 degrees C, respectively, were detected from fluctuation in the annual mean temperatures. The trend of the first period (1975-1993) is towards a cooler climate, whereas the trend of the second period (1994-2007) is towards a warmer climate. Summer, autumn and, particularly, the spring mean temperatures have tended to increase strongly, whereas the winter mean temperatures have increased slightly over the whole period. For the winter mean temperature, the trend rate indicates a slight increase, which is insignificant. Maximum temperatures have dramatically increased with 1.61 degrees C (alpha = 0.001) over the last 33 years. However, annual minimum temperatures have increased by 0.99 degrees C (alpha = 0.01) over the same period.