Campus Units

Geological and Atmospheric Sciences

Document Type

Article

Publication Version

Published Version

Publication Date

8-2013

Journal or Book Title

Journal of Hydrometeorology

Volume

14

Issue

4

First Page

1228

Last Page

1242

DOI

10.1175/JHM-D-12-0112.1

Abstract

The authors analyze the ability of global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) multimodel ensemble to simulate very heavy daily precipitation and its supporting processes, comparing them with observations. Their analysis focuses on an upper Mississippi region for winter (December–February), when it is assumed that resolved synoptic circulation governs precipitation. CMIP5 GCMs generally reproduce well the precipitation versus intensity spectrum seen in observations to intensities as strong as 20 mm day−1. Most models do not produce the highest precipitation intensities seen in observations. Models show good agreement at the 95th percentile, while the coarsest resolution models generally show lower precipitation at high-intensity thresholds, such as the 99.5th percentile. There is no dominant month for simulated very heavy events to occur, although observed very heavy events occur most frequently in December. Further analysis focuses on precipitation events exceeding the 99.5th percentile that occur simultaneously at several points in the region, yielding so-called “widespread events.” Examination of additional fields during widespread very heavy events shows that the models produce these events under the same physical conditions seen in the observations. The coarsest models generally produce similar behavior, although features have smoother spatial distributions. However, the resolution in itself could not be identified as a major reason that separates one model from another. The capabilities of the CMIP5 GCMs examined here support using them to assess changes in very heavy precipitation under future climate scenarios.

Comments

This article is from Journal of Hydrometeorology 14 (2013): 1228–1242, doi:10.1175/JHM-D-12-0112.1. Posted with permission.

Copyright Owner

American Meteorological Society

Language

en

File Format

application/pdf

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