Elevation-Dependency of Regional Warming over the Central Andes Mountains

Climate variability and change in South America affect millions of people and impact water resources, agriculture, economic activity, human health, ecosystems and biodiversity. The South American Monsoon System (SAMS) is the most important climatic feature in the continent. South America has warmed significantly over the last several decades, and climate model projections from the Intergovernmental Panel on Climate Change confidently agree that warming will continue into the 21st century. The eastern Andes low-level winds can significantly intensify under certain synoptic and large-scale conditions forming the South America low-level jet (SALLJ). The SALLJ transports large amounts of moisture from the Amazon to the La Plata Basin and induces the formation of mesoscale convective systems that bring substantial amounts of precipitation.

The Weather Research and Forecasting (WRF) model is used in this study to investigate regional warming in South America. WRF is configured with two nested grids with 45 km and 15 km horizontal grid sizes and 41 vertical levels. Climate Forecast System Reanalysis (CFSR) is used as initial and boundary conditions to develop dynamical downscaling over South America for the period 1 November – 31 March, 1980-2015. This presentation will discuss regional warming in South America in recent decades and the elevation dependency of such warming over the eastern slopes of the Central Andes. Potential changes in the SALLJ will also be discussed.