Magnitude, scale, and dynamics of the 2020 Mei Yu rains and floods over China

Volonte, A. ORCID: https://orcid.org/0000-0003-0278-952X, Muetzelfeldt, M. ORCID: https://orcid.org/0000-0002-6851-7351, Schiemann, R. ORCID: https://orcid.org/0000-0003-3095-9856, Turner, A. ORCID: https://orcid.org/0000-0002-0642-6876 and Klingaman, N. ORCID: https://orcid.org/0000-0002-2927-9303 (2021) Magnitude, scale, and dynamics of the 2020 Mei Yu rains and floods over China. Advances in Atmospheric Sciences, 38. pp. 2082-2096. ISSN 0256-1530 doi: 10.1007/s00376-021-1085-z

Abstract/Summary

Large parts of East and South Asia were affected by heavy precipitation and flooding during early summer 2020. This study provides both a statistical and dynamical characterization of rains and floods affecting the Yangtze River Basin (YRB). By aggregating daily and monthly precipitation over river basins across Asia, it is shown that the YRB is one of the areas that was particularly affected. June and July 2020 rainfall was higher than in the previous 20 years, and the YRB experienced anomalously high rainfall across most of its sub-basins. YRB discharge also attained levels not seen since 1998/9. An automated method detecting the daily position of the East Asian Summer Monsoon Front (EASMF) is applied to show that the anomalously high YRB precipitation was associated with a halted northward progression of the EASMF and prolonged Mei Yu conditions over the YRB lasting more than one month. Two 5-day heavy-precipitation episodes (12-16 June and 4-8 July 2020) are selected from this period for dynamical characterisation, including Lagrangian trajectory analysis. Particular attention is devoted to the dynamics of the airstreams converging at the EASMF. Both episodes display heavy precipitation and convergence of monsoonal and subtropical air masses. However, clear differences are identified in the upper-level flow pattern, substantially affecting the balance of airmass advection towards the EASMF. This study contextualises heavy precipitation in Asia in summer 2020 and showcases a number of analysis tools developed by the authors for the study of such events.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/99319
Identification Number/DOI	10.1007/s00376-021-1085-z
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Springer
Download/View statistics	View download statistics for this item