Exploring Relationships between the Land Surface and Large-Scale Atmospheric Circulation Patterns over Southeastern South America

To move towards increased understanding and predictability of atmospheric processes on multiple timescales, it is imperative to elucidate relationships between the land surface and atmosphere. Though existing studies have explored connections between soil moisture and planetary wave structures over North America, similar relationships over South America have not yet been studied. This work analyzes 37 years of Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) data with the goal of illuminating statistical relationships between soil moisture, geopotential height, precipitation, and 2-meter temperature over southeastern South America, where a vegetation dipole exists in the La Plata River Basin (LPRB) region. Preliminary results demonstrate statistically significant correlations between geopotential height values and precipitation in the LPRB region. A z-score composite analysis suggests that surface heating and cooling associated with the vegetation dipole has a noticeable influence on the geopotential height field. Further work analyzes output from a global climate model, with the aim of gaining enhanced insight via simulations with differing soil moisture conditions. Results yielded by this work can advance current understanding of land-atmosphere interactions and improve predictability of the climate system on monthly or seasonal timescales.