Abstract: (9038 Views)
High temperature extremes are a serious threat to society, the environment and the economics of countries. High extreme temperatures are important features of weather events. Human and natural physical caused climate change can affect climate extremes, as well as maximum temperatures. Heat waves and super-hot days occurrence was increased in recent years due to global warming phenomena. Since south east of Iran is in subtropical location, it is exposed to this extreme climate frequently. In the present study, statistical analysis and identification of synoptic pattern of extreme high temperature in south east of Iran were investigated. In order to do this, firstly temperature data of nine synoptic stations in south east of Iran were collected, and then Normalized Temperature Deviation output data were calculated and by using these data, summer days were categorized into hot, sever hot and super-hot days. Increasing of hot days was concluded. Twenty seven super-hot days were chosen for synoptic analysis. Gang thermal low pressure on earth surface and 850 HPa level and subtropical high pressure on two levels including 700 HPa and 500 HPa cause super-hot days. Ward cluster analysis shows no variation in these patterns. Advection of temperature on hot days shows that maximum temperature was occurred in south east of Iran and not originated from abroad.
Received: 2015/01/26 | Accepted: 2015/04/6 | Published: 2016/01/21