نوع مقاله : مقاله علمی پژوهشی
نویسنده
گروه جغرافیا دانشگاه تربیت مدرس
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
The meteorological data indicate that secondary climatic features like hails, heavy showers, floods, and lightening are dominant climatic features in Tabriz during the thunderstorm occurrence. The above-mentioned climatic hazards are part of Tabriz climate characteristics and North West region. These hazards bring about a great deal of economic, social, and environmental damages, particularly for formers and animals farms.
The upper level atmospheric data available in the NationalCenter for Environmental Prediction (NCEP) have been used in this article for synoptic study of thunder rainstorm days of 24 and 25 April 2010 in Tabriz. The atmospheric conditions have been analyzed by calculations and the application of drawing methods for the thunder rainstorm occurrence period.
The results of the synoptic analysis showed that eddy and blocking have occurred at 500, 600 and 700 HP levels, along with severe convective instability at all levels of 1000 to 500 HP. Whereas positive and cyclonic vorticity in the atmospheric levels of 500, 600, 700 and 850 HP were affective factors in occurrence of thunder rainstorms during the days of 24 and 25 April 2010. Moisture advection maps showed that the moisture supply source of thunder rainstorms are on 1000 HP levels, while 925 and 850 HP levels of the Caspian Sea and on 700, 600 and 500 HP levels of the Mediterranean and Black seas have occurred during the days 24 and 25 April 2010 in Tabriz and North West of Iran.
کلیدواژهها [English]