The influence of general circulation patterns on humid and dry years in the cuyo andean region of argentina

Abstract

Due to the population growth in the agricultural areas under irrigation in Cuyo (West Central Argentina), the consequences of fluctuations in cordillerean river regimes, whose snowfalls provide water for irrigation, have begun to be felt acutely in recent years.Hemispheric and regional circulation patterns associated with two extreme hydrological (drought and excess) situations in Cuyo were investigated, searching for links between both scales.Important anomalies of hemispheric and regional occurrences have been observed when droughts and floods occur at the regional scale (upper level of the mountain range central Andes and Chilean Mediterranean zone).Precipitation fluctuations show a direct or inverse association with other South American Regions (Uruguay and Islas Orcadas del Sur) and also an important teleconnection between phenomena of extratropical latitudes.The anomalous monthly average pressure fields (regional scale) are generated by an increase (20 to 30 per cent over the normal frequency) of a few persistent synoptic models, and by a westerly wave with ridge or trough over Mas Orcadas del Sur (South Orkncys Is.) or towards the west of Juan Fernandez.

Variability in subtropical Andean Argentinean Atuel river; a wavelet approach

“…This caused a dramatic shortage of water available for irrigation and hydropower that aected the local economies. In the mid-1970s the situation reversed; snowstorms increased as did the river discharges (Minetti and Sierra 1989).…”

A note on ground thermal regimes and global solar radiation at 4720 m a.s.l., High Andes of Argentina

“…Unfortunately, no precipitation data from the Central Cordillera are available. An extrapolated value of roughly 400 mm/yr can be taken as an approximation (Minetti et al, 1986;Minetti and Sierra, 1989). The low precipitation contrasts with high potential evaporation (Burgos and Vidal, 1951;Prohaska, 1976), caused by high radiation throughout the year.…”

Soya bean yield variability in the Argentine Pampas in relation to synoptic weather types: monitoring implications

“…Persistent synoptic conditions or larger-scale events frequently occur in the region, causing extreme rainfall (Malaka and Nuñez, 1980;Casarin and Kousky, 1986;Minetti and Sierra, 1989;Minetti et al, 1993;Alessandro and Lichtenstein, 1996;Alessandro, 1996Alessandro, , 2000Labraga et al, 2002). The impact of climate adversities on agricultural activities makes it necessary to determine to what extent climate spatial and temporal variability is responsible for crop yields and to generate elements to monitor, estimate impacts and design an alert system.…”