Changes in temperature extremes for 21st century scenarios over South America derived from a multi-model ensemble of regional climate models

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

CLIMATE RESEARCH

INTER-RESEARCH

Lugar: Oldendorf/Luhe; Año: 2016

0936-577X

This study examines a set of 4 temperature extreme indices (cold and warm night-time and daytime indices) from an ensemble of 4 regional climate models (RCMs) for present andfuture periods in South America (SA). These models were integrated in the framework of theCLARIS-LPB 7FP-EU-project. We analyze the capability of RCMs to reproduce such indices andexplore changes projected by the models under the scenario A1B for the end of the 21st century.The work also analyzes the role of cloudiness, surface radiative forcing and meridional wind com-ponents on temperature extremes. Future projections show that, during the austral summer, theincrease in the frequency of warm nights is larger than that projected for warm days. This resultagrees with the projections for the seasonal mean fields of minimum temperature (TN) versus themaximum temperature (TX) over most of SA. The analysis for the La Plata Basin suggests that thisbehavior is consistent with the cooling effect of cloud cover affecting TX, while TN is affected bynighttime greenhouse warming. The relationship between cloudiness and TN and TX anomaliesshows a nonlinear behavior for near full cloud cover conditions. Although TX and TN anomaliesare sensitive to strong cold air advection, TX is more sensitive than TN. Thus, RCMs are usefultools to analyze both the spatial pattern of temperature extremes and the climatic factors involved.