Divergent surface and total soil moisture projections under global warming

Geophysical Research Letters
By: , and 

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Abstract

Land aridity has been projected to increase with global warming. Such projections are mostly based on off-line aridity and drought metrics applied to climate model outputs but also are supported by climate-model projections of decreased surface soil moisture. Here we comprehensively analyze soil moisture projections from the Coupled Model Intercomparison Project phase 5, including surface, total, and layer-by-layer soil moisture. We identify a robust vertical gradient of projected mean soil moisture changes, with more negative changes near the surface. Some regions of the northern middle to high latitudes exhibit negative annual surface changes but positive total changes. We interpret this behavior in the context of seasonal changes in the surface water budget. This vertical pattern implies that the extensive drying predicted by off-line drought metrics, while consistent with the projected decline in surface soil moisture, will tend to overestimate (negatively) changes in total soil water availability.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Divergent surface and total soil moisture projections under global warming
Series title Geophysical Research Letters
DOI 10.1002/2016GL071921
Volume 44
Issue 1
Year Published 2017
Language English
Publisher American Geophysical Union
Contributing office(s) National Research Program - Eastern Branch
Description 9 p.
First page 236
Last page 244