Document Type : Research Paper

Authors

• Fatemeh Dargahian
• Gholam Hossein Rezaei

Abstract

Since the temperature declared by meteorological stations is the only reading of the temperature inside the screen box regardless of other atmospheric parameters including humidity, it cannot therefore indicate our real sense of the air temperature, because warm air is sensed warmer in case of high humidity, so that when the temperature is 35 ° C, it is felt about 43 ° C if the relative humidity is 55 percent. In this paper, the method of calculating the heat index was used to calculate the real sensed temperature in warm months of June, July, and August for a period of 10 years in 40 synoptic stations in the southern part of the country, and the results were zoned in the ArcGIS software environment as the real sensed isothermal maps and were compared with common isothermal maps. The results show that during the warm season, despite the fact that the southern coastal regions of the country show lower temperature, but have a higherreal sensed temperature, which reducesby getting away from the coast and the reduction of the humidity.  In the southern coastal regions of the country, the high real sensed temperature, especially when the heat waves are created, causes problems for the people. Given the real sensed temperature thresholds, the frequency of problems was classified in four categories, each class creating special conditions. The synoptic conditions of a heat wave, which have led to the increase in the real sensed temperature, and the location of coastal stations in extremely dangerous conditions, were investigated. The results show that the prediction and timely warning issuance of heat waves, by the meteorological organization based on this indicator for the warm and humid regions of the country, can lead to the reduction in the casualties caused by this event.

Keywords

• Heat index
• Synoptic pattern
• Coastal stations
• Temperature and Humidity