Document Type : Research Paper

Authors

• Hasan Lashkari ¹
• Noshin Aghasi ²

¹ Department of Geography, University of Shahid Beheshti

² Shahid Beheshti University of Climatology

Abstract

The thunderstorms are climate destroyer phenomena every year entering irreversible losses on the establishments, farms, houses and so on such as the hail, the flooding rains and the thunder strike. The recognition of the role of these storms is very important that can decrease the possible losses. In the present research after the analyzing the thermodynamic and synoptic characteristics about the Tabriz thunderstorms in a statistical ten-year period (1996-2005) and ensuring the results of the instability indicators, the researches show strong anticyclone dominance on Russia which extends to the westernorth of Iran and causes increasing thermal gradiant at this area. Also in the higher levels, the presence of strong cyclones on the eastern south of the black sea due to the constant raining of the northern latitudes on this area has caused high depth of the entering path of the black sea on the north western of Iran. With the insertion of two low pressure cells of Sudan and Mediterranean on Kuwait and south of Iraq and with the extention of it's dominance toward the western north of Iran and also the presence of a low pressure cell on Hormoz strait and north of Arabia and finally the transfering of heat and the moisture of Oman sea and the Persian Gulf on the areas have provided the necessary conditions for the higher instability and the thunderstrikes.

Keywords

• Thunderstorm
• Tabriz
• synoptic analysis
• Unstability