TY - JOUR
T1 - Sensitivity to Horizontal Resolution of Regional Climate Model in Simulated Precipitation over Kyushu in Baiu Season
AU - Fukui, Shin
AU - Murata, Akihiko
N1 - Funding Information:
We are grateful to two anonymous reviewers for their valuable comments. We also thank Mr. Masaya Nosaka, Dr. Hiroaki Kawase and Dr. Shunichi Watanabe of Meteorological Research Institute for helping us to perform the simulations. This work was supported by the Integrated Research Program for Advancing Climate Models (TOUGOU) Grant Number JPMXD0717935561 from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.
Publisher Copyright:
© The Author(s) 2021. This is an open access article published by the Meteorological Society of Japan under a Creative Commons Attribution 4.0 International (CC BY 4.0) license (http://creativecommons.org/license/by/4.0).
PY - 2021
Y1 - 2021
N2 - This study statistically investigated sensitivities of simulated precipitation to horizontal resolution of a regional climate model, instead of focusing on particular cases. We performed long-term integrations of models with horizontal grid spacings of 20, 5, 2, 1, and 0.5 km over Kyushu in the Baiu seasons of 2009−2020. The 2-km grid model improves simulated precipitation to the 5-km grid models with and without cumulus parameterization. Further decreasing the gird spacing from 2 km to 1 and 0.5 km reduces the dependency of the frequency biases on intensities of hourly precipitation and mitigates the excessive concentration of heavy precipitation in small scale, approaching that of the radar/raingauge analysis. The features of individual deep moist convections, specifically the horizontal scale of updrafts, the representation of downdrafts, and the number of convections, start to converge when the grid spacing is reduced from 1 to 0.5 km. The results suggest models with grid spacing of 1 km or less are needed to resolve deep moist convections and to represent the resulting precipitations. The 2-km grid models can partly resolve the deep moist convections, but their effective resolution is still insufficient, requiring some parameterizations to simulate convective precipitations appropriately.
AB - This study statistically investigated sensitivities of simulated precipitation to horizontal resolution of a regional climate model, instead of focusing on particular cases. We performed long-term integrations of models with horizontal grid spacings of 20, 5, 2, 1, and 0.5 km over Kyushu in the Baiu seasons of 2009−2020. The 2-km grid model improves simulated precipitation to the 5-km grid models with and without cumulus parameterization. Further decreasing the gird spacing from 2 km to 1 and 0.5 km reduces the dependency of the frequency biases on intensities of hourly precipitation and mitigates the excessive concentration of heavy precipitation in small scale, approaching that of the radar/raingauge analysis. The features of individual deep moist convections, specifically the horizontal scale of updrafts, the representation of downdrafts, and the number of convections, start to converge when the grid spacing is reduced from 1 to 0.5 km. The results suggest models with grid spacing of 1 km or less are needed to resolve deep moist convections and to represent the resulting precipitations. The 2-km grid models can partly resolve the deep moist convections, but their effective resolution is still insufficient, requiring some parameterizations to simulate convective precipitations appropriately.
UR - http://www.scopus.com/inward/record.url?scp=85121461785&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85121461785&partnerID=8YFLogxK
U2 - 10.2151/SOLA.2021-036
DO - 10.2151/SOLA.2021-036
M3 - Article
AN - SCOPUS:85121461785
SN - 1349-6476
VL - 17
SP - 207
EP - 212
JO - Scientific Online Letters on the Atmosphere
JF - Scientific Online Letters on the Atmosphere
ER -
