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

LLUÍS FITA BORELL; CLAUDIO G. MENENDEZ; PABLO G. ZANINELLI; ANDREA F. CARRIL; ROMINA C. RUSCICA; PEDRO FLOMBAUM; ANNA SÖRENSSON

Beijing

Congreso; ICRC-CORDEX 2019; 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 theatmospheric circulation of South America with large differences in the climatic response that occur onthe windward and lee side of the range. Due to different representations of the mountain, thewindward and lee sides will differ among the models. Moreover, the climate along the mountain rangewill present a strong dependence on the topographical high of the grid point, also differing amongmodels, and its distance from the Equator. In order to take under consideration all these elements, wepresent the first results of a methodology which allows us to objectively classify the domain ofsimulation following three different criteria: latitudinal bands, topographical height and W-E side alongthe range. The methodology is applied to analyze the climate change projection and its uncertainty ofall over the South American Andes mountain range. This range encompasses a large variety of climatesalong its North-South distribution and presents also strong W-E climate differences due to its blockingeffect to the large-scale circulation. The databases used include a sub-set of CMIP5 runs, availableCORDEX runs, and some re-analysis in order to provide a robust measure of the uncertainty spannedby these models presented at different, latitudes, heights and sides of the mountains.