Investigating the Atmospheric Structure of the Von Phenomenon at the Time of Forest Fires in Northern Iran

Document Type : Research Article

Authors

• Faramarz khoshakhlagh ¹
• Hasan Haji Mohammadi ²
• Hosein Koshky ³

¹ Associate Professor in Natural Geography,University of Tehran, Tehran, Iran

² PhD Candidate in Climatology,Tarbiat Modares University , Tehran, Iran

³ PhD Candidate in Climatology, University of Tehran, Tehran, Iran

10.22067/geoeh.2022.76403.1219

Abstract

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. So, 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 studied period, the event of January 25-31, 2007 was one of the strongest and most pervasive phones that occured 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 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. Moreover, by the ascent of the air mass on the Alborz mountain range, its moisture discharge, the passage of the air over the mountain, and its flow in the region and the heatless heat, the hot and dry air mass entered the region which had been accompanied by strong winds affecting fire-prone areas. With an increase in wind speed and a positive temperature drop, a sudden jump and increase in temperature had taken place. Trackings also showed that the main source of flow entering the region is in the northern part of the Persian Gulf and northeastern Africa.

Graphical Abstract

Keywords

• Wind Phone
• Fire
• Pressure Gradient
• Northern Iran
• Synoptic

Main Subjects

• مخاطرات اقلیمی و اتمسفریک

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