Future Atmospheric Rivers and Impacts on Precipitation: Overview of the ARTMIP Tier 2 High-Resolution Global Warming Experiment
Christine A. Shields, Ashley E. Payne, Eric Jay Shearer, Michael F. Wehner, Travis Allen O’Brien, Jonathan J. Rutz, L. Ruby Leung, F. Martin Ralph, Allison B. Marquardt Collow, Paul A. Ullrich, Qizhen Dong, Alexander Gershunov, Helen Griffith, Bin Guan, Juan Manuel Lora, Mengqian Lu, Elizabeth McClenny, Kyle M. Nardi, Mengxin Pan, Yun Qian, Alexandre M. Ramos, Tamara Shulgina, Maximiliano Viale, Chandan Sarangi, Ricardo Tomé, Colin Zarzycki | March 14th, 2023
Atmospheric rivers (ARs) are long and narrow weather features often referred to as “rivers in the sky.” They often transport water from lower latitudes to higher latitudes typically across climate zones and produce precipitation necessary for local climates. Understanding ARs in a warming climate is challenging because of the variety of ways an AR can be defined on gridded data sets. Unlike weather
features such as tropical cyclones where identification methodologies are similar, algorithms that determine the characteristics of ARs vary depending on the science question posed. Because there is no real consensus on AR identification methodology, we aim to quantify the algorithmic uncertainty in AR metrics and precipitation.
We compare 16 different ways of defining an AR on gridded data sets and present the range of possibilities in which an AR could change under global warming. Generally, ARs are projected to increase but the amount of that increase is a function of the algorithm. Across all algorithms and focus regions, AR precipitation is projected to become more extreme.
Keywords
atmospheric rivers, climate change, flood management, modeling, water supply forecasting