Increased amplitude of atmospheric rivers and associated extreme precipitation in ultra-high-resolution greenhouse warming simulations

Abstract

Atmospheric rivers play an integral role in the global water cycle, but predicting their future changes remains uncertain due to inter-model and inter-detection-method differences. Using ultra-high-resolution Community Earth System Model simulations and a novel detection algorithm based on geometric shape extraction, we quantify global changes in atmospheric rivers and the associated precipitation events in response to doubling and quadrupling of atmospheric CO2 concentrations. We find that, atmospheric rivers are projected to become more frequent and more likely to be associated with extreme precipitation events, increasing their contribution to global mean precipitation. While the water vapor transport within these structures follow Clausius-Clapeyron scaling, the changes in maximum precipitation intensity resemble other saturated atmospheric environments like tropical cyclone cores. The increased amplitude of atmospheric rivers and the associated increase in mean and extreme precipitation have important implications for future water management and adaptation policies.