Statistical analysis of temperature changes in Israel: An application of change point detection and estimation techniques

The main goal of this study is to present and apply recently developed nonparametric change point detection and estimation techniques for confirming patterns of regional changes in temperature. Utilizing these methods, monthly temperatures (mean, mean maximum, mean minimum) and diurnal temperature ranges in different regions of Israel have been investigated over a period of 37-years, (1967-2003). The results were supported also by traditional statistical methods. The temperature and the diurnal temperature range analyses reveal a complex pattern of change. In particular, we found an increase in the monthly mean temperatures in the warm season in all areas of Israel approximately from the mid-1980s to the mid-1990s, namely, the summers have become warmer. Also detected was a significant increase in the monthly mean minimum temperature in Israel's coastal plain area for all months of the year. Whereas, in mountainous and desert areas a significant increase in the monthly mean minimum temperature was detected only in months of the warm season. The winters have become warmer in the Israeli coastal plain and have not significantly changed in its mountainous and desert areas. In addition, in Israel's coastal plain the monthly mean DTRs are decreasing, while in mountainous and desert areas the situation is reversed, that is, monthly mean DTRs are increasing.