TY - JOUR
T1 - Improvement in the modeled representation of North American monsoon precipitation using a modified Kain-Fritsch convective parameterization scheme
AU - Luong, Thang M.
AU - Castro, Christopher L.
AU - Nguyen, Truong M.
AU - Cassell, William W.
AU - Chang, Hsin I.
N1 - Publisher Copyright:
© 2018 by the authors.
PY - 2018/1/19
Y1 - 2018/1/19
N2 - A commonly noted problem in the simulation of warm season convection in the North American monsoon region has been the inability of atmospheric models at the meso-β scales (10 s to 100 s of kilometers) to simulate organized convection, principally mesoscale convective systems. With the use of convective parameterization, high precipitation biases in model simulations are typically observed over the peaks of mountain ranges. To address this issue, the Kain-Fritsch (KF) cumulus parameterization scheme has been modified with new diagnostic equations to compute the updraft velocity, the convective available potential energy closure assumption, and the convective trigger function. The scheme has been adapted for use in the Weather Research and Forecasting (WRF). A numerical weather prediction-type simulation is conducted for the North American Monsoon Experiment Intensive Observing Period 2 and a regional climate simulation is performed, by dynamically downscaling. In both of these applications, there are notable improvements in the WRF model-simulated precipitation due to the better representation of organized, propagating convection. The use of the modified KF scheme for atmospheric model simulations may provide a more computationally economical alternative to improve the representation of organized convection, as compared to convective-permitting simulations at the kilometer scale or a super-parameterization approach.
AB - A commonly noted problem in the simulation of warm season convection in the North American monsoon region has been the inability of atmospheric models at the meso-β scales (10 s to 100 s of kilometers) to simulate organized convection, principally mesoscale convective systems. With the use of convective parameterization, high precipitation biases in model simulations are typically observed over the peaks of mountain ranges. To address this issue, the Kain-Fritsch (KF) cumulus parameterization scheme has been modified with new diagnostic equations to compute the updraft velocity, the convective available potential energy closure assumption, and the convective trigger function. The scheme has been adapted for use in the Weather Research and Forecasting (WRF). A numerical weather prediction-type simulation is conducted for the North American Monsoon Experiment Intensive Observing Period 2 and a regional climate simulation is performed, by dynamically downscaling. In both of these applications, there are notable improvements in the WRF model-simulated precipitation due to the better representation of organized, propagating convection. The use of the modified KF scheme for atmospheric model simulations may provide a more computationally economical alternative to improve the representation of organized convection, as compared to convective-permitting simulations at the kilometer scale or a super-parameterization approach.
KW - Convective parameterization scheme
KW - North American monsoon
KW - Regional climate modeling
UR - http://www.scopus.com/inward/record.url?scp=85040786181&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85040786181&partnerID=8YFLogxK
U2 - 10.3390/atmos9010031
DO - 10.3390/atmos9010031
M3 - Article
AN - SCOPUS:85040786181
SN - 2073-4433
VL - 9
JO - Atmosphere
JF - Atmosphere
IS - 1
M1 - 31
ER -