Future hydroclimatological changes in South America based on an ensemble of regional climate models

ZANINELLI P.; MENÉNDEZ C. G.; FALCO M.; LÓPEZ DE LA FRANCA AREMA, N; CARRIL A. F.

CLIMATE DYNAMICS

SPRINGER

Lugar: Berlin; Año: 2018

0930-7575

p { margin-bottom: 0.25cm; line-height: 120%; }a:link { color: rgb(0, 0, 255); }Changesin hydroclimatological conditions for South America have beenexamined using an ensemble of regional climate models. Annualmean precipitation (P), evapotranspiration (E) and potentialevapotranspiration (EP)arejointly consideredthrough the balances of land waterandenergy. Dryingor wetting conditions, associated with changes in land wateravailability and atmospheric demand, are analysed in the Budykospace. The water supply limit (E limited by P) is exceeded at about2% of the grid points, while the energy limit to evapotranspiration(E = EP)is overall valid. Most of the continent, except for the southeast andsome coastal areas, presents a shift toward drier conditions relatedto a decrease in water availability (the evaporation rate E / Pincreases) and, mostly over much of Brazil, to an increase in thearidity index (Ф = EP/ P). These changes suggest less humid conditions with decreasingsurface runoff over Amazonia and the Brazilian Highlands. Incontrast, Argentina and the coasts of Ecuador and Peru arecharacterized by a tendency toward wetter conditions associated withan increase of water availability and a decrease of aridity index,primarily due to P increasing faster than both E and EP.This trend towards wetter soil conditions suggest that the chances ofhaving larger periods of flooding and enhanced river discharges wouldincrease over parts of south eastern South America. Interannualvariability increases with Ф and with climate change. In particular,interannual variability increases over the Brazilian Highlands anddecreases in central-eastern Argentina.