Summer and winter precipitation in East Asia scale with global warming at different rates

Wengui Liang,Minghua Zhang

doi:10.1038/s43247-021-00219-2

Abstract

Future changes of regional precipitation are of great scientific and societal interests. Large uncertainties still exist in their projections by models. Mechanistic understanding is therefore necessary. Here we demonstrate robust features of the percentage change of precipitation normalized to surface temperature change (%/K) under global warming, referred to as scaling of precipitation with temperature in East Asia. We find that land precipitation in the summer scales at ~3%/K, well below the scaling rate of the Clausius-Clapeyron relationship for atmospheric water vapor content, but the scaling in winter is comparable to the Clausius-Clapeyron scaling at ~7%/K. By using moisture budget analysis of model simulations, we show that this scaling and the seasonal contrast can be clearly attributed to the robust climate changes of steeping moisture gradient, weakening westerly jets, and increasing hydrological amplitude of atmospheric eddies.

Highlights

Future changes of regional precipitation are of great scientific and societal interests
The theory is built upon the robust climate change features of steepening moisture gradient[16,24,30,31,32] and weakening of westerly jet[15,25,33,34,35,36,37,38], which have been extensively reported in the literature, and separation of dynamical and hydrological amplitudes of atmospheric eddies, the latter of which can be interpreted as larger discharge of moisture in a warmer climate during precipitation events
Surface warming in East Asia is projected to be stronger at higher latitudes, more over land than over the ocean, and larger in the winter (December to February, DJF) than in the summer (June to August, JJA)

Summary

Introduction

Future changes of regional precipitation are of great scientific and societal interests. Model projections of future changes in precipitation display large inter-model differences with much larger spatial variations than the warming. The theory is built upon the robust climate change features of steepening moisture gradient[16,24,30,31,32] and weakening of westerly jet[15,25,33,34,35,36,37,38], which have been extensively reported in the literature, and separation of dynamical and hydrological amplitudes of atmospheric eddies, the latter of which can be interpreted as larger discharge of moisture in a warmer climate during precipitation events

Methods

Results

Conclusion