Using 15-yr data from the European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA15), the authors found that rapid southeastward expansion of the rainy area from the western Amazon to southeastern Brazil is a result of midlatitude cold air intrusions. During austral spring, as the large-scale thermodynamic structure over Amazonia becomes destabilized, the incursions of extratropical...

The meteorological conditions during the period of spring transition over the Middle East and the Persian Gulf and adjacent land area is investigated. Monthly and seasonal variations of large-scale atmospheric patterns and wind aloft features at different levels were drawn from data collected from the National Centers for Environmental Prediction and National Center for Atmospheric Researches. ...

The effects of rapid Arctic warming and ice loss on weather patterns in the Northern Hemisphere is a topic of active research, lively scientific debate and high societal impact. The emergence of Arctic amplification--the enhanced sensitivity of high-latitude temperature to global warming--in only the last 10-20 years presents a challenge to identifying statistically robust atmospheric responses...

the southern coasts of caspian sea is subjected to synoptic/mesoscale weather systemsranging from locally enhanced sea breeze formation and small local front systems to synoptic scale cyclones.this study presents climatology of cyclones over the southern coasts of caspian sea covering a ten year period1996-2005. altogether 57 cyclones were formed during the ten year period. anoticeable seasonal...

introduction thunderstorms of the most important, most abundant of the most severe weather hazard that each year, in addition to large quantities of crops and infrastructure development, causing human casualties are also around the globe. between 1953 and 1957 the financial losses caused by the hurricanes in america has over 3.6 million dollars (changnon;2003,1231).storms of varying intensities...

Weather surveillance radars observe clear-air radar echoes (CAE); aerial biota and irregularities in atmospheric refractive index caused the echoes. Using weak returns of atmospheric CAE, the radars have been applied to wind findings in a short radar range in a fair weather, in particular S-band radars. Long wavelength radars perform good to observe air motion, because a detectable turbulent sc...

drought is one of the natural disasters that causes a lot of damages each year. this phenomenon is a result of severe and repeated spatial-temporal anomalies in atmosphere circulation patterns. thus, studying and identifying the synoptic patterns of this phenomenon is inevitably necessary. in this study, first yearly rainfalls in selected stations of the uremia lake basin were temporally standa...

The Madden-Julian Oscillation (MJO) is a tropical atmospheric phenomenon, associated with periods of active convection in the eastern hemisphere tropics.The MJOs temporal scale (22-90 days) coincides with a gap between weather (synoptic forecasts out to 10 days) and climate (seasonal and longer forecasts).Analysis of 35 years of daily rainfall data shows significant modulation of tropical and e...