Variability and Changes in Temperature, Precipitation and Snow in the Desaguadero-Salado-Chadileuvú-Curacó Basin, Argentina

Abstract

We analyze the variability and changes in mean temperature, annual precipitation, and snow water equivalent (SWE) in the Desaguadero-Salado-Chadileuvú-Curacó (DSCC) basin, observed in a recent period, and their projected future values. The current climate and observed changes are studied based on the scarce observation records available in the region. Simulations from the High-Resolution Model Intercomparison Project (HighResMIP v1.0) are used for the analysis of future climate projections. The mean annual temperature presents a major rise between 1 and 2 °C throughout the region in the 1961–2020 period. The annual precipitation has nonlinear positive trends of varied importance. The SWE has decreased noticeably since 2010. Interannual variability also plays a key role, with dominant cycles between 2.8 and 4 years and between 7.5 and 10 years. The projected changes, computed as the difference between the 1985–2014 and 2021–2050 averages, reveal a rise in mean annual temperature in the entire basin, with an eastward magnitude increase from 1 to more than 2 °C. The annual precipitation is projected to increase up to 10% over most of the basin, except in the Andes, where it will decrease. The maximum annual SWE will also continue to decrease, in agreement with the trend observed in recent years.