ENSO Influence over Precipitation in Argentina

EUGENIA GARBARINI; MARIA SKANSI; MARCELA HEBE GONZALEZ; ALFREDO LUIS ROLLA

Advances in Environmental Research

NOVA Publisher

Lugar: NY; Año: 2016; p. 223 - 246

Argentina is located in southeastern South America and because of its extensive territory, areas with different climate features can be found. The main climate features are related to the moisture advection from the Brazilian forest in the north, from the South Atlantic High in the east and the frequent front passages from the southwest. All these features are highly influenced by the presence of Los Andes Mountain extending all along the west of the country. Some teleconnection patterns also influence seasonal climate, for example the El Niño-Southern Oscillation and the Indian Dipole. In these cases sea surface temperature anomalies in tropical oceans act as remote forcing generating Rossby wave trends which propagate meridionally towards middle-latitudes and arrive to western Argentina. In this chapter, the relation between these teleconnection forcings and seasonal precipitation is investigated in order that they can be used as rainfall predictors. The results indicate that the relationship depends on the season and the region of Argentina. It can be noticed that warm (cold) phase of El Niño and a positive (negative) phase of Indian Dipole are all related to increased (decreased) spring and autumn precipitation in northeastern Argentina and Central Andes and the signal decreases in summer and winter. Finally, the relationship between the last warm phase of El Niño beginning in 2015 and seasonal rainfall in Argentina is detailed.