Interannual Variation and Regime Shift of the Evaporative Moisture Sources for Wintertime Precipitation Over Southern China. Issue 23 (4th December 2018)

• Record Type: Journal Article
• Authors: Yang, Zifan; Huang, Wenyu; Qiu, Tianpei; He, Xinsheng; Wright, Jonathon S.; Wang, Bin
• Is Part Of: Journal of geophysical research. Volume 123:Issue 23(2018)
• Page Start: 13, 168
• Page End: 13, 185
• Publication Date: 2018-12-04
• Subjects: evaporative moisture source -- Lagrangian approach -- eastward migration -- interannual variation -- regime shift; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2018JD029513
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: The evaporative moisture source for wintertime precipitation over southern China during 1979–2017 is determined using a Lagrangian methodology. The five most important moisture source regions, in descending order, are the South China Sea, southern China (local moisture recycling), southeastern Asia, the East China Sea, and the western North Pacific. The dominant mode of variability of moisture contribution appears at the interannual time scale, which is closely related to the El Niño Southern Oscillation variability. The conventional El Niño signal favors moisture transport from the surrounding moisture source regions through an enhancement of an anticyclonic anomaly over the western North Pacific, while El Niño Modoki drives moisture recycling over southern China by cutting off access to moisture sources from surrounding regions. A regime shift of the evaporative moisture source is identified to occur around 1991/1992, after which there was a significant eastward migration of the moisture source. This migration is closely related to the presence of a cyclonic anomaly over the South China Sea. Both the observational and experimental results reveal that the appearance of this cyclonic anomaly is due to the warming over the Maritime Continent during the last two decades. Key Points: The moisture contribution from the South China Sea is modulated by the circulation pattern rather than evaporation from ocean surface The two types of El Nino have distinct impacts on the moisture contribution An eastward migration of the moisture source occurred during 1991/1992, owing to the Maritime Continent warming