Improvements in WRF simulation skills of southeastern United States summer rainfall: physical parameterization and horizontal resolution
Abstract
Realistic regional climate simulations are important in understanding the mechanisms
of summer rainfall in the southeastern United States (SE US) and in making seasonal
predictions. In this study, skills of SE US summer rainfall simulation at a 15-km
resolution are evaluated using the weather research and forecasting (WRF) model driven
by climate forecast system reanalysis data. Influences of parameterization schemes
and model resolution on the rainfall are investigated. It is shown that the WRF simulations
for SE US summer rainfall are most sensitive to cumulus schemes, moderately sensitive
to planetary boundary layer schemes, and less sensitive to microphysics schemes. Among
five WRF cumulus schemes analyzed in this study, the Zhang-McFarlane scheme outperforms
the other four. Further analysis suggests that the superior performance of the Zhang-McFarlane
scheme is attributable primarily to its capability of representing rainfall-triggering
processes over the SE US, especially the positive relationship between convective
available potential energy and rainfall. In addition, simulated rainfall using the
Zhang-McFarlane scheme at the 15-km resolution is compared with that at a 3-km convection-permitting
resolution without cumulus scheme to test whether the increased horizontal resolution
can further improve the SE US rainfall simulation. Results indicate that the simulations
at the 3-km resolution do not show obvious advantages over those at the 15-km resolution
with the Zhang-McFarlane scheme. In conclusion, our study suggests that in order to
obtain a satisfactory simulation of SE US summer rainfall, choosing a cumulus scheme
that can realistically represent the convective rainfall triggering mechanism may
be more effective than solely increasing model resolution. © 2014 Springer-Verlag
Berlin Heidelberg.
Type
Journal articlePermalink
https://hdl.handle.net/10161/9571Published Version (Please cite this version)
10.1007/s00382-013-2031-2Publication Info
Li, Laifang; Li, Wenhong; & Jin, Jiming (2014). Improvements in WRF simulation skills of southeastern United States summer rainfall:
physical parameterization and horizontal resolution. Climate Dynamics. pp. 1-15. 10.1007/s00382-013-2031-2. Retrieved from https://hdl.handle.net/10161/9571.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Wenhong Li
Associate Professor of Climate
Dr. Li's research interests focus primarily on climate dynamics, land-atmosphere interaction,
hydroclimatology, and climate modeling. Her current research is to understand how
the hydrological cycle changes in the current and future climate and their impacts
on the ecosystems, subtropical high variability and change, unforced global temperature variability,
and climate and health issues.

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