Results of a new methodology for the analyze the climate change uncertainty on a high step mountain range. Application at the Andes

FITA BORRELL, L; A. CARRIL; FLOMBAUM, P; MENÉNDEZ C; RUSCICA R; SORENSSON A

Beijing

Congreso; ICRC-CORDEX; 2019

Multi-model climate change analysis over mountainous regions is a complex topic due to the models' different representations of the mountains. The Andes Mountains produces a huge disturbance of the atmospheric circulation of South America with large differences in the climatic response that occur on the windward and lee side of the range. Due to different representations of the mountain, the windward and lee sides will differ among the models. Moreover, the climate along the mountain range will present a strong dependence on the topographical high of the grid point, also differing among models, and its distance from the Equator. In order to take under consideration all these elements, we present the first results of a methodology which allows us to objectively classify the domain of simulation following three different criteria: latitudinal bands, topographical height and W-E side along the range. The methodology is applied to analyze the climate change projection and its uncertainty of all over the South American Andes mountain range. This range encompasses a large variety of climates along its North-South distribution and presents also strong W-E climate differences due to its blocking effect to the large-scale circulation. The databases used include a sub-set of CMIP5 runs, available CORDEX runs, and some re-analysis in order to provide a robust measure of the uncertainty spanned by these models presented at different, latitudes, heights and sides of the mountains.