Effects of the South Atlantic warming over South American precipitation

Abstract

Precipitation is arguably one of the main controlling factors of life on Earth. From food production to water availability, changes in precipitation patterns can lead to social disruption and massive economic loss. Recent findings point to a possible human-driven slowdown of the Atlantic Meridional Overturning Circulation. Such reduction could lead to the South Atlantic warming, and consequently, to changes in continental precipitation. Here we will determine the Effects of the South Atlantic warming over South American Precipitation, a strongly debated and timely subject: while some pieces of evidence point to a widespread increase in tropical South American precipitation to the south of the equator during a reduced circulation, others suggest that the increase is restricted to specific parts of the continent. Thus, a comprehensive reconstruction of changes in precipitation during such conditions is urgently needed to understand ongoing and future changes in precipitation. We will reconstruct South American precipitation during the last two millennia in unprecedented temporal and spatial resolution. Therefore, we will apply state-of-the-art precipitation proxies (i.e., hydrogen isotopes in leaf waxes and quartz luminescence sensitivity) to a suite of marine sediment cores collected off eastern equatorial, tropical and subtropical South America. The high resolution in luminescence analyses will be achieved by developing a luminescence scanner. We will then verify which fully coupled model from the Intergovernmental Panel on Climate Change best reproduce the reconstructed changes in precipitation, this validation is crucial for enhancing model reliability. Our results will ultimately inform society about future changes in precipitation promoting an efficient adaptation strategy. (AU)