the mediterranean is one of the most important cyclogenesis regions in the northern hemisphere. the depressions occurring in specific areas of the mediterranean region and cyclonic tracks have been the subject of extensive climatological research. the climate of the mediterranean region is conditioned by its position in the transition area between the sub-tropical high pressure belt and the mid...

introduction climate change is an important environmental hazard that has been discussed in recent years. increasing the number or frequency of extreme climatic events such as severe droughts, floods, storms, heat and cold waves and heavy rains are the evidences of climate change. any of these events, due to the severity and persistence and their spread are a natural hazard that adverse effects...

introduction zayanderood basin is one of the major internal river basins in the central iran, where zayanderood river is the only permanent river. fluctuations in rainfall in recent years have affected different areas of iran. because of the dependence of the provinces of isfahan, yazd, and kerman on water resources of this basin, changes and fluctuations in precipitation within this watershed ...

Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinc...

in order to determine the synoptic pattern of heavy and extreme precipitations on the southern coast of the caspian sea, precipitation characteristics of the caspian region were investigated by the use of eight synoptic stations data. considering the percentage thresholds, the days with heavy and extreme precipitations were determined for a 10 year period (1994-2003). since more than 75% of day...

1. introduction the effect of climate of the earth's surface is the result of interaction of different levels of atmosphere and lithosphere. one of the factors which influences that interaction is the way the system pressure transcends it. in this way, the system pressure changes and can be changed and eventually may become an environmental hazard and geomorphodynamic phenomenon. hazards are an...

i introduction convective systems are atmospheric events that are associated with hazardous consequences, such as strong wind drafts, lightning, heavy rainfall, hail, or even tornado. they are manifested in the atmosphere within a broad range of spatial and temporal scales. a convection cell is composed of two distinct regions: the actual convective part which consists of the coldest intense ve...