Weakened and Lowered Sensitivity of Extreme Precipitation Over the Global Land Monsoon Regions During the Last Glacial Maximum

Abstract

The Last Glacial Maximum (LGM) provides an opportunity to estimate how extreme precipitation may respond to large radiative forcing and hence the constraints for its future behavior. Using daily outputs from the Paleoclimate Modeling Intercomparison Project, we illustrate a decrease in extreme precipitation intensity over the global monsoon regions during the LGM relative to preindustrial, accompanied by increased extreme precipitation frequency, although regional differences exist. The weakened extreme precipitation is dominated by the thermodynamics (∼92%) linked to change in temperature, with the dynamic component linked to change in vertical velocity contributing to regional differences. Furthermore, we show a ∼3.6% decrease in extreme precipitation per 1°C cooling during the LGM, lower than the sensitivity (∼5%/°C) in future warming scenarios. Our results are in line with the proxies‐based drier conditions and lower equilibrium climate sensitivity during the LGM, and may advance understanding of extreme precipitation variation in a warmer future.