Rainfall patterns and the relation to atmospheric circulation in northern Patagonia (Argentina)

GONZÁLEZ, MARCELA HEBE; GARBARINI EUGENIA MARIA; ROMERO, PAULA ELISA

Advances in Environmental Research

NOVA PUBLISHER

Lugar: NUEVA YORK; Año: 2015; p. 1 - 20

The aim of this chapter is to establish the relationship between the mean annual rainfall and river flows and assess climate and oceanic climate forcing of interannual rainfall variability in northern Patagonia region in Argentina. In this region four major rivers are present: Limay, Neuquen, Negro and Colorado. A principal component (PC) method was applied to annual rainfall anomalies in order to detect behavior patterns in different years. Eight PCs resulted significant explaining 83,5% of the rainfall anomalies variance. Therefore, eight spatial patterns were described and years could be classified in different groups according to these patterns. Temporal series derived from this analysis were correlated with the mean annual flow during the hidrological year in each river. Only the first eigenvector was significantly correlated with Limay, Neuquen and Negro flows showing that positive rainfall anomalies near the Andes Mountain determined positive river flow anomalies. But none significant correlation was detected for Colorado River. Relation between climate forcing of interannual variability (for example ENSO) and rainfall anomalies patterns was analyzed and encouraging results were found.