Recognition, Classification and synoptical Analysis of Heat waves decreasing human hazards In North West of Iran

The heat waves are the main manifestations of contemporary world climate change, which in terms of the frequency of occurrence and financial and human loss caused by them are of great importance. The aim of this study was to identify, classify and analyze heat waves synoptic occurred in the Northwest of Iran, to verify the effective synoptic system in the occurrence of heat waves. In this study, the heat index introduced by the National Center for the United States weather data (NCDC) was used. For this purpose, long term statistics of 23 years old maximum daily temperature and relative humidity on a daily basis for five hottest months of the year (May to September) of Iran’s Northwest synoptic stations were collected from National Meteorological Organization and the statistical characteristics of heat waves and synoptic and occurrence of heat waves, were evaluated according this the thermal index and classified into five levels of intensity. The analysis of synoptic map showed also that the dominant patterns in the study regions next to a tropical high pressure, Saudi Arabia and Pakistan. The maps of moisture flux also showed a cyclone movement on the Caspian Sea and the Mediterranean Sea, have the most impact on the moisture flux of northwest area of Iran. there is moisture in the event of heat waves on north west area that exacerbate the risks of heat waves, in terms of human risk.