Campus Units

Agronomy, Geological and Atmospheric Sciences

Document Type

Article

Publication Version

Published Version

Publication Date

9-2004

Journal or Book Title

Geophysical Research Letters

Volume

31

Issue

17

First Page

L17109

DOI

10.1029/2004GL020528

Abstract

In the last 25 years of the 20th century most major land regions experienced a summer warming trend, but the central U.S. cooled by 0.2–0.8 K. In contrast most climate projections using GCMs show warming for all continental interiors including North America. We examined this discrepancy by using a regional climate model and found a circulation-precipitation coupling under enhanced greenhouse gas concentrations that occurs on scales too small for current GCMs to resolve well. Results show a local minimum of warming in the central U.S. (a “warming hole”) associated with changes in low-level circulations that lead to replenishment of seasonally depleted soil moisture, thereby increasing late-summer evapotranspiration and suppressing daytime maximum temperatures. These regional-scale feedback processes may partly explain the observed late 20th century temperature trend in the central U.S. and potentially could reduce the magnitude of future greenhouse warming in the region.

Comments

This article is from Geophysical Research Letters 31 (2004): L17109, doi:10.1029/2004GL020528. Posted with permission.

Copyright Owner

American Geophysical Union

Language

en

File Format

application/pdf

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