نوع مقاله : مقاله علمی پژوهشی
نویسندگان
1 دانشگاه حکیم سبزواری
2 دانشیار آب و هواشناسی دانشکده جغرافیای دانشگاه حکیم سبزواری
3 استادیار آب و هواشناسی دانشکده جغرافیای دانشگاه حکیم سبزواری
چکیده
کلیدواژهها
عنوان مقاله [English]
foehn pour warm and dry under certain conditions on the slopes of the mountains are caused by the wind. When the amplitude of the adiabatic air humidity climbs to the summit of the mountains, If you have enough moisture saturation and the formation of clouds or rain lost its moisture, dries With the passage of the mountain range behind the wind, will sink into the bottom of the valley or plain. The data used in this research include fires and meteorological data. Information on distribution time, place and the fire of the Department of Natural Resources Gilan, Mazandaran and Golestan period (1390-1384) collected data from weather elements such as temperature, humidity, wind and pressure for the three northern governorates and Semnan provinces, Tehran and Qazvin was obtained from the National Weather Service. The synoptic situation day to analyze the fire ground level pressure data, geopotential, air temperature, relative humidity, zonal and meridional wind components, sensible heat flux and instability index (omega) of the website of the National Centers for Environmental Prediction and the National Center for Atmospheric Research (NCEP / NCAR) was received. After weather conditions in the southern and northern slopes of the Alborz action synoptic maps of the three days prior to the event every forest fire GrADS software and using MODIS satellite images of the mountain clouds in time event was screened.This phenomenon (foehn) is not a local event, but the influence of the general circulation of the atmosphere and the system is moving west wind, And the ripples and the range of moisture conditions and rainfall, wind strength and weakness of will. Moving West to East West winds associated with this phenomenon
کلیدواژهها [English]