introductionmany aspect strongly influence regional climate includes localized surface processes, large-scale patterns, especially mid and upper level tropospheric circulation and many factors control precipitation in the west of iran includes location of emigrate westerly winds systems, jet streams location, humidity flux and topography. upper tropospheric jet stream constitutes a significant ...

abstract many people know the important effects of caspian sea winds and storms on the economy of three provinces of iran including gilan, mazandaran, and golestan that they form one exclusive and extent area which have moderate and humid climate. this paper used a synoptic climatologically approach, which combine a number of atmospheric factors. using daily and monthly winds data including the...

in this research, the frequency of the jet streams associated with extreme and pervasive precipitation has been analyzed using environmental to circulation approach. based on the 99th percentile index, 109 days of the extreme and pervasive precipitation was selected from the irimo data base ( including 33 synoptic, climatic and rain gage stations during 15992 days from farvardin, 1st, 1340 to d...

introduction according to the definition of world meteorology organization (wmo), as the speed of the air mass is more than 30 meters per second, the jetstream will arise. the core of the jetstream is with baroclinic atmosphere due to the large difference in temperature and wind speed. there are two west jetstreams in the northern hemisphere. the northern jet stream is called polar front jetstr...

In recent decades, southeast Australia has experienced both extreme drought and record-breaking rainfall, with devastating societal impacts. Variations in the Australian polar-front jet (PFJ) subtropical (STJ) determine, for example, location frequency of cool season (April–September) weather systems influencing rainfall events and, consequently, water availability southern half Australia. Chan...

the moisture flux convergence (mfc) and relative humidity in dusty days at different times and levels over the alvand mountain was investigated. the required basic data for the years 2009-2012, including relative humidity, visibility and synoptic codes, were gathered from hamadan synoptic station, while sea level pressure, uwind, vwind and specific humidity data were gathered from ncer/ncar sit...

Abstract Based on observation and reanalysis datasets, numerical experiments with a simple dynamical model, climate model outputs, this study investigates the second leading waveguide teleconnection along summer polar front jet (PFJ) over Eurasia interannual time scale, British–Okhotsk Corridor (BOC) pattern. The BOC pattern explains 20.8% of total variance northern Eurasia, which is only sligh...