The Representation of the Southern Annular Mode Signal in the Brazilian Earth System Model

The Southern Annular Mode (SAM, also known as the Antarctic Oscillation—AAO) explains most of climate variability in Hemisphere. A ring pattern mean sea level pressure (MSLP) or 500 hPa geopotential height around Antarctica characterizes SAM. Differences MSLP values between SH mid and high latitudes define positive negative SAM phases with impacts on atmospheric circulation. Thus, investigating how different models represent is paramount importance, it can improve their ability to describe even predict variability. Here we examine Brazilian Earth System Model (BESM) represents SAM’s signal compared observations, reanalysis, other contributing Coupled Modeling Intercomparison Project version 5 (CMIP5). We evaluate relates South American surface temperature precipitation discuss models’ limitations biases reanalysis data.