Ocean surface energy balance allows a constraint on the sensitivity of precipitation to global warming

Wei Wang,Xuhui Lee,Wei Xiao,T C Chakraborty

doi:10.1038/s41467-021-22406-7

Abstract

Climate models generally predict higher precipitation in a future warmer climate. Whether the precipitation intensification occurred in response to historical warming continues to be a subject of debate. Here, using observations of the ocean surface energy balance as a hydrological constraint, we find that historical warming intensified precipitation at a rate of 0.68 ± 0.51% K−1, which is slightly higher than the multi-model mean calculation for the historical climate (0.38 ± 1.18% K−1). The reduction in ocean surface albedo associated with melting of sea ice is a positive contributor to the precipitation temperature sensitivity. On the other hand, the observed increase in ocean heat storage weakens the historical precipitation. In this surface energy balance framework, the incident shortwave radiation at the ocean surface and the ocean heat storage exert a dominant control on the precipitation temperature sensitivity, explaining 91% of the inter-model spread and the spread across climate scenarios in the Intergovernmental Panel on Climate Change Fifth Assessment Report.

Highlights

Climate models generally predict higher precipitation in a future warmer climate
We find that historical changes in a, β and surface longwave radiation intensified global P, and changes in surface shortwave radiation and ocean heat storage weakened P, with the former slightly outweighing the latter
We hypothesize that changes in global precipitation ΔP are driven primarily by changes in ocean evaporation ΔEO at the annual and longer time scales

Summary

Introduction

Climate models generally predict higher precipitation in a future warmer climate. Whether the precipitation intensification occurred in response to historical warming continues to be a subject of debate. Using observations of the ocean surface energy balance as a hydrological constraint, we find that historical warming intensified precipitation at a rate of 0.68 ± 0.51% K−1, which is slightly higher than the multi-model mean calculation for the historical climate (0.38 ± 1.18% K−1). A well-known thermodynamic consequence of greenhouse gasinduced warming is the increase of water vapor abundance in the atmosphere This atmospheric moistening is responsible for about half of the increase in the longwave radiation[4,5] and for almost all the reduction in the clear-sky shortwave radiation[5] or solar dimming at the Earth’s surface. We extend the framework to diagnose climate model predictions of future P change, revealing a robust emergent relationship of ΔP/ΔT with two key surface energy components

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Conclusion