in this research, the correlation between precipitation change in southern coasts of caspian sea and variability of sea level pressure have been analyzed by using environmental to circulation approach at time period 1339- 1383. in this respect, we make use of daily precipitation data of the 12 synoptic stations of studied area at surface data base section and prepare the time series matrix of p...

introduction there are significant differences in the spatial distribution of the iran annual precipitation. this is resulted from spatial behavior of precipitation in the one hand and variation in the sources of precipitation on the other. the lack of adequate distribution of meteorological stations and the unavailability of long-term statistics of precipitation makes the analysis of precipita...

prediction of precipitation is very important. regarding to the non- linear relationships and uncertainty of models, there is no superior and persuasive model among various proposed models to simulate precise precipitation and its amount. wavelet is one of the novel and very effective methods in time series and signals analyzing, that has been considered in the field of hydrology in recent year...

An archive of land-based, surface-observed cloud reports has been updated and now spans 39 years from 1971 through 2009. Cloud-type information at weather stations is available in individual reports or in longterm, seasonal, and monthly averages. A shift to a new data source and the automation of cloud reporting in some countries has reduced the number of available stations; however, this datas...

This study is devoted to the evaluation of the role of assimilation of conventional data on the quantitative precipitation forecasts at regional scale. The conventional data included surface station reports as well as upper air observations. The analysis was based on the simulation of 15 cases of heavy precipitation that occurred in the Eastern Mediterranean. The verification procedure revealed...

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...