This paper presents an analysis of the frequency and spatial distribution of droughts in Argentina during the 20th century. Special attention is given to the mean monthly atmospheric circulation associated with dry conditions in the Pampas during the second half of the century. A reduction in the number of dry cases is found throughout the century, especially during the warm season (October to ...

Neural network models are used to reveal the nonlinear winter atmospheric teleconnection patterns associated with the El Niño-Southern Oscillation (ENSO) and with the Arctic Oscillation (AO) over the N. Hemisphere. The nonlinear teleconnections (for surface air temperature, precipitation, sea level pressure and 500 hPa geopotential height) are found to relate quadratically to the ENSO and AO in...

Dust storm is a natural hazardous phenomenon that affects arid and semi-arid regions of the world same as Iran. The present research aims to investigate formation synoptic patterns pervasive dust storms (PDSs) in southwestern For this purpose, daily data visibility less than 1000m 16 stations (Ilam Khuzestan provinces) were reviewed during 2004–2017, 59 PDSs with more 2 days duration (overlappe...

the aim of this research is the assessment of the relation between rainfall and large scale synoptically patterns at khorasan razavi province. in this study, using adaptive neuro fuzzy inference system, the rainfall estimation has been done from april to june in the area under study. spring rainfall data including the information of 38 synoptic, climatologic and rain gauge stations from 1970 to...

The occurrence of major avalanche episodes in the Eastern Pyrenees (NE Spain) is estimated by means of the Poisson and the negative binomial distributions, assuming that they are rare events. The differences observed in their spatial distribution along the seven regions in which Eastern Pyrenees have been divided, suggests us to look for spatial variations in the relationship between extreme av...