Investigation of the atmospheric structure of the Von phenomenon at the time of forest fires in northern Iran

Document Type : Research Article


1 Department of Natural Geography, University of Tehran, Faculty of Geography

2 Department of Natural Geography, Faculty of Geography, University of Tehran

3 PhD Student in Synoptic Meteorology, Tarbiat Modares University، ،Tehran


In order to investigate the atmospheric mechanisms governing the occurrence of the Von phenomenon at the time of forest fires in northern Iran, four types of data were used in the research, changes in parameters such as temperature, pressure and wind were investigated. Networked data from the National Environmental Prediction / Atmospheric Science Centers (NCEP / NCAR) and the European Center for Medium-Term Atmospheric Prediction (ECMWF) were then used to explain the structure of the atmosphere. Modis sensor images were used to study the surface temperature of the earth and suspended airborne particle model was used to track air masses. It was found that during the study period, the event of January 25-31, 2007 is one of the strongest and most pervasive phones that occur in the region. The results showed that by forming a high pressure cell located in the south of the country and a low pressure cell in the wind protection part of Alborz mountain, it has created a strong pressure gradient and has caused the south current to affect the northern regions of Iran. Accordingly, during a static-dynamic process, a wind turbine rotational current has been formed in the Alborz mountain range wind turbine, with the ascent of the air mass on the Alborz mountain range and also its moisture discharge and the passage of the air package over the mountain and its flow in the region and the heatless heat, the hot and dry air mass enters the region which is accompanied by strong winds Has been affected by fire-prone areas. With an increase in wind speed and a positive temperature drop there is a sudden jump and increase in temperature tracking also showed that the main source of current entering the region is in the northern part of the Persian Gulf and northeastern Africa.


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