introduction the dynamic state index (dsi) is being introduced on the basis of a newly developed theory termed the energy-vorticity theory (evt). as a weather index, the dsi can describe the temporal sequence and intensity of areas of high and low pressure; but as a climate index, it can also diagnose climate change based on the variation in solar radiation or the influences of friction. in phy...

The relationship between South American precipitation and cross-equatorial flow over the western Amazon is examined using the 15-yr (1979–93) European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis dataset. A meridional wind index, the V index, is constructed to represent the variability of the crossequatorial flow, based on area-averaged (58S–58N, 658–758W) daily 925-hPa meridion...

The relationship between precipitation and large-scale measures of atmospheric circulation has received much attention in recent years (e.g. Bardossy & Caspary, 1990; Bardossy & Plate, 1992; Hughes et al., 1993; Woolhiser et al., 1993; Katz & Parlange, 1993). Some of the interest relates to quantifying the possible change in atmospheric circulation within the past two decades, with associated c...

Various drought monitoring models have been developed from different perspectives, as drought is impacted by various factors (precipitation, evaporation, runoff) and usually reflected in various aspects (vegetation condition, temperature). Cloud not only plays an important role in the earth's energy balance and climate change, but also directly impacts the regional precipitation and evaporation...

introduction selection of the clear and transparent index for the precipitation using long-term homogeneous data is an important point for the researchers. several investigations have led to different indices for heavy rainfall. in some cases the specific amount of precipitation was used for heavy rainfall (rahimzadeh, 2005; masoodian, 2008; kamiguchi et al., 2006), e.g. alijani (2002) has sugg...

precipitation regime refers to distribution of seasonal- monthly precipitation. by studying this character, it could be find out about the most important parts of mechanism(s) dominant in temporal distribution of precipitation. precipitation regime can have positive or negative effects on other environmental components performance. in the present research, the monthly data in 73 stations during...

Satellite estimates and weather forecast models have made it possible to observe and predict precipitation over large spatial scales. Despite substantial progress in observing patterns of precipitation, characterization of spatial patterns is still a challenge. Quantitative assessment methods for spatial patterns are essential for future developments in prediction of the spatial extent and patt...

abstract drought is one the most complicated and unknown natural disasters and rainfed agriculture is often the first sector to be affected by drought. in this research, we consider the drought monitoring from both meteorological and agricultural points of view. we have selected standardized precipitation index (spi) among the meteorological indices, with a one month time scale for the synoptic...