Homogeneity and Trend Analysis of Long Term Temperatures in the Middle Black Sea Region

Abstract

In this study long-term trend analysis of maximum and minimum monthly temperatures are determined in the Middle Black Sea Region of Turkey. Data is obtained from Turkish State Meteorological Service for the period of 1964 to 2015 for Amasya, Çorum, Ordu, Samsun, Sinop and Tokat stations throughout the Middle Black Sea Region. Primarily homogeneity of the data is examined with Run, Buishand and Von Neumann homogeneity methods with a 99 % confidence level. Linear trend, Mann-Kendall and Innovative Sen’s trend methods are used for trend analysis with a 99 % and 95 % confidence levels. Amasya and Çorum stations are determined homogeny according to the entire homogeneity tests. Ordu is homogeny for Run test besides Samsun, Sinop and Tokat stations are homogeny for the Von Neumann test. The maximum temperatures showed an increasing significant trend, while the minimum temperatures showed increasing trends statistically insignificant. The results of Mann-Kendall and the Linear trend analysis are similar. The Sen’s method was consistent with linear and Mann-Kendall tests, except for the minimum temperatures of the Amasya and Tokat stations. Since the confidence interval is very sensitive in Sen’s trend method, trends in most of the stations have been determined increasing. Trends of monthly maximum and minimum temperatures are analyzed in the study. The data of 1964-2015 periods of six stations in the Middle Black Sea region were taken into consideration. Long-term trends in all trend analysis were determined that increasing significant trends are seen in maximum and minimum temperatures.