Relationship between variations in temperature and salinity of the South Atlantic surface and South American precipitation over the last two millennia

• Grant number: 24/07420-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2024
• End date: January 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Chemical Oceanography
• Principal Investigator: Vinícius Ribau Mendes
• Grantee: Viviane Korres Bisch
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated research grant: 22/02957-0 - Effects of the South Atlantic warming over South American precipitation, AP.PNGP.PI

Abstract

Precipitation is arguably one of the main controlling factors of life on Earth. From foodproduction to water availability, changes in precipitation patterns can lead to social disruption andmassive economic loss. Recent findings point to a possible human-driven slowdown of the AtlanticMeridional Overturning Circulation. Such reduction could lead to the South Atlantic warming, andconsequently, to changes in continental precipitation. Here we will determine the Effects of theSouth 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 Americanprecipitation to the south of the equator during a reduced circulation, others suggest that theincrease is restricted to specific parts of the continent. Thus, a comprehensive reconstruction ofchanges in precipitation during such conditions is urgently needed to understand ongoing andfuture changes in precipitation. We will reconstruct South American precipitation during the lasttwo 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 luminescencesensitivity) to a suite of marine sediment cores collected off eastern equatorial, tropical andsubtropical South America. The high resolution in luminescence analyses will be achieved bydeveloping a luminescence scanner. We will then verify which fully coupled model from theIntergovernmental Panel on Climate Change best reproduce the reconstructed changes inprecipitation, this validation is crucial for enhancing model reliability. Our results will ultimatelyinform society about future changes in precipitation promoting an efficient adaptation strategy.