Open AccessDifferences in precipitation efficiency and their probable mechanisms between the warm sector and cold front stages of a heavy rainfall event over Beijing
Author(s) -
Mao Jiahua,
Ping Fan,
Li Xiaofan,
Yin Lei
Publication year - 2018
Publication title -
atmospheric science letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.951
H-Index - 45
ISSN - 1530-261X
DOI - 10.1002/asl.802
Subject(s) - precipitation , environmental science , cold front , beijing , troposphere , advection , snow , climatology , water vapor , atmospheric sciences , front (military) , airflow , warm front , meteorology , geology , geography , mechanical engineering , physics , archaeology , engineering , china , thermodynamics
A heavy rainfall event that occurred in Beijing on July 21, 2012 was simulated successfully using the Weather Research and Forecasting model, and the precipitation efficiency (PE) during different rainfall stages was studied. The results showed that both the large‐scale precipitation efficiency (LSPE) and the cloud‐microphysics precipitation efficiency (CMPE) in the peak of the warm sector stage (T1) were significantly higher than those in the cold front stage (T2). The higher LSPE was related to the water vapor advection, which played a positive role in T1 due to the warm and moist advection in the lower troposphere, and a negative role in T2 because of the cold and dry airflow in the middle level. The snow‐related microphysical processes had similar tendencies to the CMPE, in which the higher rain–snow collection and deposition of water vapor brought about the higher CMPE in T1. Analysis of the underlying mechanisms proved that the LSPE and CMPE were subject to the large‐scale environment and cloud microphysical features.