Improved simulation of extreme precipitation in a high-resolution atmosphere model

Journal Article · Tue Oct 29 00:00:00 EDT 2013 · Geophysical Research Letters

DOI:https://doi.org/10.1002/2013gl057866· OSTI ID:1565100

Kopparla, Pushkar ^[1]; Fischer, Erich M. ^[1]; Hannay, Cécile ^[2]; Knutti, Reto ^[1]

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1. ETH Zürich, Zürich (Switzerland). Inst. for Atmospheric and Climate Science
2. National Center for Atmospheric Research, Boulder, CO (United States)

Climate models often underestimate the magnitude of extreme precipitation. We compare the performance of a high-resolution (~0.25°) time-slice atmospheric simulation (1979–2005) of the Community Earth System Model 1.0 in representing daily extreme precipitation events against those of the same model at lower resolutions (~1° and 2°). We find significant increases in the simulated levels of daily extreme precipitation over Europe, the United States, and Australia. In many cases the increase in high percentiles (>95th) of daily precipitation leads to better agreement with observational data sets. For lower percentiles, we find that increasing resolution does not significantly increase values of simulated precipitation. We argue that the reduced biases mainly result from the higher resolution models resolving more key physical processes controlling heavy precipitation. Lastly, we conclude that while high resolution is vital for accurately simulating extreme precipitation, considerable biases remain at the highest available model resolutions.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
• Sponsoring Organization: USDOE Office of Science (SC)
• OSTI ID: 1565100
• Journal Information: Geophysical Research Letters, Vol. 40, Issue 21; ISSN 0094-8276
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
geology
atmospheric model
extreme precipitation
high resolution
GCM