TY - JOUR
T1 - Impacts of microphysical scheme on convective and stratiform characteristics in two high precipitation squall line events
AU - Wu, Di
AU - Dong, Xiquan
AU - Xi, Baike
AU - Feng, Zhe
AU - Kennedy, Aaron
AU - Mullendore, Gretchen
AU - Gilmore, Matthew
AU - Tao, Wei Kuo
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2013/10/16
Y1 - 2013/10/16
N2 - This study investigates the impact of snow, graupel, and hail processes on simulated squall lines over the Southern Great Plains in the United States. The Weather Research and Forecasting (WRF) model is used to simulate two squall line events in Oklahoma during May 2007, and the simulations are validated against radar and surface observations. Several microphysics schemes are tested in this study, including the WRF 5-Class Microphysics (WSM5), WRF 6-Class Microphysics (WSM6), Goddard Cumulus Ensemble (GCE) Three Ice (3-ice) with graupel, Goddard Two Ice (2-ice), and Goddard 3-ice hail schemes. Simulated surface precipitation is sensitive to the microphysics scheme when the graupel or hail categories are included. All of the 3-ice schemes overestimate the total precipitation with WSM6 having the largest bias. The 2-ice schemes, without a graupel/hail category, produce less total precipitation than the 3-ice schemes. By applying a radar-based convective/stratiform partitioning algorithm, we find that including graupel/hail processes increases the convective areal coverage, precipitation intensity, updraft, and downdraft intensities, and reduces the stratiform areal coverage and precipitation intensity. For vertical structures, simulations have higher reflectivity values distributed aloft than the observed values in both the convective and stratiform regions. Three-ice schemes produce more high reflectivity values in convective regions, while 2-ice schemes produce more high reflectivity values in stratiform regions. In addition, this study has demonstrated that the radar-based convective/stratiform partitioning algorithm can reasonably identify WRF-simulated precipitation, wind, and microphysical fields in both convective and stratiform regions. Key Points The 3-ice scheme increases convective area, precipitation, but reduces stratiform All schemes overestimated reflectivity at midlevels, especially 2-ice schemes The partitioning scheme identifies convective and stratiform regions reasonably
AB - This study investigates the impact of snow, graupel, and hail processes on simulated squall lines over the Southern Great Plains in the United States. The Weather Research and Forecasting (WRF) model is used to simulate two squall line events in Oklahoma during May 2007, and the simulations are validated against radar and surface observations. Several microphysics schemes are tested in this study, including the WRF 5-Class Microphysics (WSM5), WRF 6-Class Microphysics (WSM6), Goddard Cumulus Ensemble (GCE) Three Ice (3-ice) with graupel, Goddard Two Ice (2-ice), and Goddard 3-ice hail schemes. Simulated surface precipitation is sensitive to the microphysics scheme when the graupel or hail categories are included. All of the 3-ice schemes overestimate the total precipitation with WSM6 having the largest bias. The 2-ice schemes, without a graupel/hail category, produce less total precipitation than the 3-ice schemes. By applying a radar-based convective/stratiform partitioning algorithm, we find that including graupel/hail processes increases the convective areal coverage, precipitation intensity, updraft, and downdraft intensities, and reduces the stratiform areal coverage and precipitation intensity. For vertical structures, simulations have higher reflectivity values distributed aloft than the observed values in both the convective and stratiform regions. Three-ice schemes produce more high reflectivity values in convective regions, while 2-ice schemes produce more high reflectivity values in stratiform regions. In addition, this study has demonstrated that the radar-based convective/stratiform partitioning algorithm can reasonably identify WRF-simulated precipitation, wind, and microphysical fields in both convective and stratiform regions. Key Points The 3-ice scheme increases convective area, precipitation, but reduces stratiform All schemes overestimated reflectivity at midlevels, especially 2-ice schemes The partitioning scheme identifies convective and stratiform regions reasonably
KW - WRF
KW - microphysics
KW - precipitation
KW - squall line
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U2 - 10.1002/jgrd.50798
DO - 10.1002/jgrd.50798
M3 - Article
AN - SCOPUS:84887183463
VL - 118
SP - 11,119-11,135
JO - Journal of Geophysical Research Atmospheres
JF - Journal of Geophysical Research Atmospheres
SN - 2169-8996
IS - 19
ER -