Improvement in the representation of the North American monsoon convective precipitation in a 20-year climate simulation using a modified Kain-Fritsch convective parameterization scheme
Abstract
A modified Kain-Fritsch (KF) convective parameterization scheme (CPS) has been written that includes a new diagnostic equation to compute updraft velocity, closure assumption, and trigger function. These modifications take the vertical gradient of pressure perturbation into account, making the scheme more appropriate for complex terrain. In this research we use the Weather Research and Forecasting Model (WRF) with NCEP reanalysis boundary forcing to simulate organized convections in the North American monsoon region from 1990 to 2010. With a cold bias of the sea surface temperature (SST) input in the summer over the Gulf of California (GoC), WRF failed to capture the precipitation pattern in the southwest U.S. and area near the coast of GoC. Correcting the SST bias and using modified KF CPS yields improved representation of the monsoon precipitation, in comparison to several observational proxies. The positive precipitation bias over the mountain is reduced and there is a more pronounced westward propagation of organized convection toward the coast.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.A13L..07L
- Keywords:
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- 3335 ATMOSPHERIC PROCESSES North American Monsoon;
- 3355 ATMOSPHERIC PROCESSES Regional modeling;
- 3329 ATMOSPHERIC PROCESSES Mesoscale meteorology