Diagnosis and Attribution of a Seasonal Precipitation Deficit in a U.S. Regional Climate Simulation
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Date
2004Author
Gutowski, William J.
Otieno, Francis O.
Arritt, Raymond W.
Takle, Eugene S.
Pan, Zaitao
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Precipitation from a 10-yr regional climate simulation is evaluated using three complementary analyses: self-organizing maps, bias scores, and arithmetic bias. Collectively, the three reveal a precipitation deficit in the south-central United States that emerges in September and lingers through February. Deficient precipitation for this region and time of year is also evident in other simulations, indicating a generic problem in climate simulation.
Analysis of terrestrial and atmospheric water balances shows that the 10-yr average precipitation error for the region results primarily from a deficit in horizontal water vapor convergence. However, the 10-yr average for fall only suggests that the primary contributor is a deficit in evapotranspiration. Evaluation of simulated temperature and soil moisture suggests the model has insufficient terrestrial water for evaporation during fall. Results for winter are mixed; errors in both evapotranspiration and lateral moisture convergence may contribute substantially to the precipitation deficit. The model reproduces well both the time-average and time-filtered large-scale circulation, implying that the moisture convergence error arises from an error in simulating mesoscale circulation.
URI
http://journals.ametsoc.org/doi/abs/10.1175/1525-7541%282004%29005%3C0230%3ADAAOAS%3E2.0.CO%3B2http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/36689
Citation
Regional Climate Simulation. J. Hydrometeor, 5, 230–242.Publisher
Univesity of Nairobi Department of Medicine
Collections
- Faculty of Health Sciences (FHS) [10387]