Projected Change in Extreme Precipitation due to Global Warming in a Large Ensemble Climate Simulation

Abstract

High-resolution atmospheric, climate large-ensemble simulations are used to assess future changes in heavy rainfall events. In most parts of the world, the rate of increase in precipitation is noticeably larger for events occurring once in 100 years than those occurring once every year. The increase can be decomposed into two contributions. One is that from water vapor in the atmosphere that increases ~7% per 1-K temperature rise. The other is that from upward motion that lifts up near-surface water vapor to condensate into rainfall. The simulation results show that the upward motion in the middle and upper troposphere conspicuously increases for the events occurring once in 100 years.