توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱A Quantitative Study of the Effect of Persian Gulf and Oman Sea as Humidity Sources for Synoptic Systems in Iran
اطلاعات انتشار: اولین کارگاه مشترک ایران و کره در مدلسازی اقلیم، سال
تعداد صفحات: ۱۱
A regional climate model (RegCM3) with horizontal resolution of 40 km in 18 vertical levels, Haltslag global boundary scheme, Grell convection parameterization and Fritsch– Chappell scheme for simulation of mesoscale systems is used for the study of climate of the region in the winter season of "2003–2004". The region concerned extends from 20 to 40 degree north in latitude and from 45 to 65 degree east in longitude, covering Oman Sea and Persian Gulf as arguably the main humidity sources for the synoptic systems. Starting from a control experiment, some specifically designed experiments were performed in which the surface characteristics over the water bodies were changed. Comparison of the model output for monthly accumulated precipitation in the control experiment with the analyzed, observed charts of accumulated precipitation indicates that the model can forecast precipitation reasonably well both temporally and spatially over the region. In different experiments, Persian Gulf and Oman Sea waters were removed, separately and together, in order to find out their individual contributions to the amount of precipitation over the region.<\div>

۲The Effect of Sea Surface Temperature and 2m Air Temperature on Precipitation Events in the Southern Coasts of Caspian Sea
اطلاعات انتشار: ECOPERSIA، دورهجديد،اول،شماره۴، Autumn ۲۰۱۳، سال
تعداد صفحات: ۱۵
There are a number of ideas to generate cloud and precipitation in the southern coasts of Caspian Sea, but none of them explain the cause of precipitation particularly heavy and super heavy precipitations precisely. This study describes main thermodynamic factors when the situation and location of synoptic patterns are effective. On the basis of daily data, monthly regimes and monthly trends of the Sea Surface Temperature (SST), difference between 2m air temperature and SST over the Caspian Sea as well as the SST gradients in different distances on latitude and its anomaly were calculated. For recognition of synoptic conditions, humidity advection, geopotential and sea level pressure maps were drawn. The results showed that there are three thermodynamic factors over the Caspian Sea to produce precipitation particularly from September to December. The first factor is arrangement and well organized of the SST gradients as it decreases from the south to the north of Caspian Sea. Also, the SST over the Sea must be enough warm to produce clouds and precipitation. The last factor is the difference between 2m air temperature and SST. When the synoptic patterns in different pressure levels are suitable for instability, the air–sea interaction process is the most important factor to produce the advection humidity, clouds and precipitation particularly heavier precipitation events in the north of Iran.
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