introduction occurrence of heavy and rainstorm events is among the characteristics of arid and semi-arid regions all over the world and particularly in iran which is causing large floods and debris town. how ever, they can be used to supply and store water by controlling and exploiting the run off water floods. indexes of atmospheric instability are very useful scientific instruments to underst...

Temperature and precipitation extremes and their potential future changes are evaluated in an ensemble of global coupled climate models participating in the Intergovernmental Panel on Climate Change (IPCC) diagnostic exercise for the Fourth Assessment Report (AR4). Climate extremes are expressed in terms of 20-yr return values of annual extremes of near-surface temperature and 24-h precipitatio...

Disclaimer Alberta Environment funded this study for the Climate Change Research Users Group. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. The author, not the publisher, is responsible for the conclusions and opinions expressed. SUMMARY This report examines recent studies on trends and changes in extreme weather events in Canada and as...

Despite the popularity of the conveyor-belt model for portraying the airflow through midlatitude cyclones, questions arise as to the path of the cold conveyor belt, the lower-tropospheric airflow poleward of and underneath the warm front. Some studies, beginning with Carlson’s analysis of the eastern U.S. cyclone of 5 December 1977, depict the cold conveyor belt moving westward, reaching the no...

The proper knowledge of spatial precipitation structure is important as much as that of microphysics processes for reliable quantitative precipitation forecasts. This study considers some aspects of how precipitation is organized on mesoand fine-scales, within a cold front line and how moisture transport is driven by these structures. Also, a spectral space vision of the representativeness erro...

one of the most important impact of climate change is reduction of precipitation in some areas including iran. hence, climate change studies are essential in these areas. besides, according to ipcc, some meteorological stations of iran, such as tabriz (capital of east azerbaijan province) have showed a downward trend in precipitation. therefore, east azerbaijan province was selected as the stud...