TY - JOUR
T1 - Contrasting pre-Mei-Yu and Mei-Yu extreme precipitation in the Yangtze river valley
T2 - Influencing systems and precipitation mechanisms
AU - Wang, Xiaokang
AU - Dong, Xiquan
AU - Deng, Y. I.
AU - Cui, Chunguang
AU - Wan, Rong
AU - Cui, Wenjun
N1 - Funding Information:
Acknowledgments. This research is supported by National Natural Science Foundation of China with grants of 41705019, 41620104009, 91637211 and at IHR. Yi Deng is in part supported by the U.S. National Science Foundation through Grants AGS-1354402 and AGS-1445956. The daily precipitation data, surface observations, and radar data are provided by the National Meteorological Information Center of the China Meteorological Administration. The CFSR data is obtained from the network (https://rda.ucar.edu/pub/cfsr.html). The WPR data at Wuhan weather station are provided by the Institute of Heavy Rain, China Meteorological Administration. Recognition is also extended to those responsible for the operation and maintenance of the instruments that produced the data used in this study. Special thanks to Mr. Theodore McHardy for reading the manuscript carefully and correcting the English.
Funding Information:
This research is supported by National Natural Science Foundation of China with grants of 41705019, 41620104009, 91637211 and at IHR. Yi Deng is in part supported by the U.S. National Science Foundation through Grants AGS-1354402 and AGS-1445956. The daily precipitation data, surface observations, and radar data are provided by the National Meteorological Information Center of the China Meteorological Administration. The CFSR data is obtained from the network (https://rda.ucar.edu/pub/cfsr.html). The WPR data at Wuhan weather station are provided by the Institute of Heavy Rain, China Meteorological Administration. Recognition is also extended to those responsible for the operation and maintenance of the instruments that produced the data used in this study. Special thanks to Mr. Theodore McHardy for reading the manuscript carefully and correcting the English.
Publisher Copyright:
© 2019 American Meteorological Society.
PY - 2019
Y1 - 2019
N2 - The mei-yu season over the Yangtze–Huai Rivers basin, typically occurring from mid-June to mid-July, is one of three heavy-rainfall periods over China and can contribute 50% of the annual precipitation. In this study, the first and second heaviest daily precipitation events at the Wuhan station have been selected to represent typical mei-yu and pre-mei-yu precipitation events where the differences in the atmospheric thermodynamic characteristics, precipitation nature, influencing systems, and mechanisms are investigated. During the mei-yu case, moist air mainly came from the South China Sea. Precipitation occurred south of the mei-yu front where abundant moisture and favorable thermodynamic conditions were present. The main influencing systems include a stable blocking pattern and strong and stable western Pacific subtropical high in the midtroposphere, and a small yet intense mesoscale cyclonic vortex in the low troposphere. Rainfall in Wuhan was continuous, caused by a well-organized convective line. A heavy rainband was located along the narrow band between the elongated upper-level jet (ULJ) and the low-level jet (LLJ) where the symmetric instability was found in the midtroposphere near Wuhan. Quite differently, for the pre-mei-yu precipitation case, moist air primarily came from the Beibu Gulf and the Bay of Bengal. Precipitation happened in the low-level convective instability region, where a short-wave trough in the midtroposphere and a mesoscale cyclonic vortex in the low-troposphere were found. Precipitation in Wuhan showed multiple peaks associated with independent meso-b-scale convective systems. A rainstorm occurred at the exit of the LLJ and the right entrance of the ULJ, where convective instability exited in the mid-to low troposphere.
AB - The mei-yu season over the Yangtze–Huai Rivers basin, typically occurring from mid-June to mid-July, is one of three heavy-rainfall periods over China and can contribute 50% of the annual precipitation. In this study, the first and second heaviest daily precipitation events at the Wuhan station have been selected to represent typical mei-yu and pre-mei-yu precipitation events where the differences in the atmospheric thermodynamic characteristics, precipitation nature, influencing systems, and mechanisms are investigated. During the mei-yu case, moist air mainly came from the South China Sea. Precipitation occurred south of the mei-yu front where abundant moisture and favorable thermodynamic conditions were present. The main influencing systems include a stable blocking pattern and strong and stable western Pacific subtropical high in the midtroposphere, and a small yet intense mesoscale cyclonic vortex in the low troposphere. Rainfall in Wuhan was continuous, caused by a well-organized convective line. A heavy rainband was located along the narrow band between the elongated upper-level jet (ULJ) and the low-level jet (LLJ) where the symmetric instability was found in the midtroposphere near Wuhan. Quite differently, for the pre-mei-yu precipitation case, moist air primarily came from the Beibu Gulf and the Bay of Bengal. Precipitation happened in the low-level convective instability region, where a short-wave trough in the midtroposphere and a mesoscale cyclonic vortex in the low-troposphere were found. Precipitation in Wuhan showed multiple peaks associated with independent meso-b-scale convective systems. A rainstorm occurred at the exit of the LLJ and the right entrance of the ULJ, where convective instability exited in the mid-to low troposphere.
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U2 - 10.1175/JHM-D-18-0240.1
DO - 10.1175/JHM-D-18-0240.1
M3 - Article
AN - SCOPUS:85073772180
SN - 1525-755X
VL - 20
SP - 1961
EP - 1980
JO - Journal of Hydrometeorology
JF - Journal of Hydrometeorology
IS - 9
ER -