orography plays a substantial role in the formation and evolution of many atmospheric phenomena. observations indicate that two mountain ranges to the southwest of the red sea and west of iran (zagross mountain range) play a crucial role in the formation, evolution and activities of synoptic weather systems over iran. observations also, indicate that there are considerable differences between t...

introduction although temperatures in 0 and below 0 c° in the cold season of the year and mid latitudes are not necessarily considered an extreme phenomenon, but their long-term durability in a widespread area or their sudden occurrence in the beginning and end of the cold season can make this faetor an extreme extent phenomenon. the extreme phenomena are resulted from interaction between large...

It is well known that some techniques have already been developed to automatically subdivide texts into multiparagraph subtopic passages, such as TextTiling methodology proposed by Hearst. However, an additional algorithm is needed to perform a similar task for parallel or variant texts, because ambiguous and complicated traces of cross citation among them might often generate some sinuous patt...

The authors argue that certain aspects of the rotational, synoptic-scale disturbances of the wind field that are observed in ITCZ or monsoon trough regions can be understood by considering the linear response of a dry, initially resting atmosphere to a pulse of heating whose amplitude and spatial and temporal scales are characteristic of a large mesoscale convective system. The key points are t...

Flood is known as one of the most distractive natural disaster worldwide. Therefore, its prediction is of great importance from the socio-economical point of view. Despite the great improvement in computational techniques and numerical weather prediction approaches, so far, in Iran, an acceptable flood prediction method has not yet been introduced. The main aim of this study is to recognize and...

[1] Using the ERA-40 reanalysis data, we study the different roles of synoptic and low-frequency eddies in sustaining the latitudinal shift of the low-level baroclinicity associated with the Southern Hemisphere Annular Mode. The eddy effect is assessed through the direct eddy thermal forcing via eddy heat flux and the indirect forcing via eddy-driven mean meridional circulation (MMC). We find t...