Precipitation in Northeast Mexico Primarily Controlled by the Relative Warming of Atlantic SSTs

Reconstructing hydroclimate over the Common Era is essential for understanding the dominant mechanisms of precipitation change and improving climate model projections, which currently suggest Northeast Mexico will become drier in the future. Tree-ring reconstructions have suggested regional rainfall is primarily controlled by Pacific sea-surface temperatures (SSTs). However, tree ring records tend to reflect winter-spring rainfall, and thus may not accurately record total annual precipitation. Using the first multiproxy speleothem record spanning the last millennium, combined with results from an atmospheric general circulation model, we demonstrate mean annual rainfall in Northeast Mexico is highly sensitive to Atlantic SST variability. Our findings suggest future precipitation in Northeast Mexico is more dependent upon the warming of Tropical Atlantic SSTs relative to the Tropical Pacific.

Automated summary

Reconstructing hydroclimate over the Common Era is important for understanding precipitation change mechanisms. The study found that mean annual rainfall in Northeast Mexico is highly sensitive to Atlantic sea-surface temperature variability, suggesting future precipitation will be more dependent on the warming of Tropical Atlantic than the Tropical Pacific.