نتایج جستجو برای: geopotential high at 500 hpa level
تعداد نتایج: 5424958 فیلتر نتایج به سال:
The main purpose of this paper is to analyze some characteristics of gravity waves (GWs), and seasonal variations of atmospheric waves over Istanbul by using wavelet techniques. Daily radiosonda data of Istanbul in the troposphere and lower stratosphere (1000 hPa–30 hPa) between 1993 and 1997 have been considered. Wavelet analysis based on a computer simulation of data is generally close to the...
Arasbaran is one of most important regions in terms of agriculture, economics and tourism in northwest of Iran that it usually receives the most yearly spring precipitation. To recognize the synoptic patterns of the 500 hpa, geopotential height data were driven for coordinates 00-70 ˚ E and 15- 65˚N in rainy springs (1972-1976-1979-1981-1986).To select the most important component using princi...
The Southern Annular Mode (SAM, also known as the Antarctic Oscillation—AAO) explains most of climate variability in Hemisphere. A ring pattern mean sea level pressure (MSLP) or 500 hPa geopotential height around Antarctica characterizes SAM. Differences MSLP values between SH mid and high latitudes define positive negative SAM phases with impacts on atmospheric circulation. Thus, investigating...
in this study, frequency and location of frontogenesis related to heavy rainfall have been analyzed using environmental to circulation approach. based on the threshold of upper 99 percent, we selected 125 days of the super and overall heavy rainfall from irimo data base (included 1437 synoptic, climatic and rain gage stations from 21/3/1961 up to 31/12/2004). frontogenesis frequency and their l...
We present a new statistical method to optimally link local weather extremes to large-scale atmospheric circulation structures. The method is illustrated using July-August daily mean temperature at 2m height (T2m) time-series over the Netherlands and 500 hPa geopotential height (Z500) time-series over the Euroatlantic region of the ECMWF reanalysis dataset (ERA40). The method identifies pattern...
A study of severe hailstorm (with size ?3 cm) over Spain has been conducted using 8 years (2012–2019) data. The 73 events heavy hail selected were classified the moisture flux at 850 hPa pressure level (qv)850 and lifted index (LI) as variables a principal component analysis, coupled with K-means clustering, statistical technique. application this procedure provided four groups their respective...
Introduction: increasing dusty storms has been one of the most important consequences of climate change in recent years that directly or indirectly affected human society. Countries located in the arid and semiarid regions of the world, including Iran, have been affected more than other parts of the globe by this natural disaster and its harmful consequences, especially the atmospheric dust, wh...
Abstract The influence of Rossby waves emitted in the northeastern Pacific Ocean on Northern Hemisphere’s atmosphere during summer is analysed using ERA5 reanalysis and a new large ensemble performed with EC-Earth3 model. Wave Sources (RWS) trigger wave-like patterns arising from upper troposphere north-eastern region, causing response around Hemisphere alternating regions positive negative cor...
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