Precipitation characteristics related to atmospheric rivers in East Asia. (7th October 2020)

• Record Type: Journal Article
• Authors: Kim, Jinwon; Moon, Hyejin; Guan, Bin; Waliser, Duane E.; Choi, Juntae; Gu, Tae‐Young; Byun, Young‐Hwa
• Is Part Of: International journal of climatology. Volume 41(2021)Supplement 1
• Page Start: E2244
• Page End: E2257
• Publication Date: 2020-10-07
• Subjects: analysis -- atmospheric river -- climate -- East Asia -- extreme precipitation -- geophysical sphere -- hydrology -- scale -- tools and methods; Climatology -- Periodicals; Climat -- Périodiques; Climatologie -- Périodiques; 551.605
• DOI: 10.1002/joc.6843
• Languages: English
• ISSNs: 0899-8418

Abstract

Abstract: Precipitation related to atmospheric rivers (ARs) is critical in shaping climate and extreme hydrologic events in the mid‐latitude coastal regions, making it a recent topic of intense research. This study has analysed the AR climatology, AR‐precipitation characteristics and their regional variations in East Asia (EA) for 1979–2015 using an AR inventory based on vertically‐integrated water‐vapour transport and AR geometry. The AR frequency over EA varies seasonally with highest (lowest) frequency in summer (winter). The AR frequency peaks in the coastal regions of the mid‐latitude western North Pacific (WNP), then decreases rapidly away from the region towards higher/lower latitudes and inlands. ARs are related to 30–60% of the annual precipitation in EA with maximum in summer; secondary peaks occur in spring in eastern China, Korea and southern Japan, and in winter for the southern China coast. Calculating the AR precipitation on days of partial AR occurrences from daily precipitation data is a key source of uncertainties in the AR‐precipitation fraction in this study. The AR days are substantially more related to heavy precipitation than non‐AR days for all seasons and regions. Seasonal cycle of AR frequency over EA and the WNP follows the northward march of the main rainband from spring to mid‐summer, but is decoupled from it from late summer to winter as the North Pacific storm track migrates into the Eastern North Pacific. The annual cycle of AR frequency and AR precipitation varies regionally; Japan and southern China adjacent to WNP show high (low) frequency of weak‐ (heavy‐) precipitating ARs in early spring (late fall) with highly frequent heavy‐precipitating ARs in summer while the mid‐latitude coastal regions, eastern China and Korea, show low frequency of heavy‐precipitating ARs in early fall with highly frequent heavy‐precipitating ARs in mid‐summer. Abstract : Precipitation related to atmospheric rivers (ARs) like shown in the image is important in shaping the regional hydroclimate in East Asia (EA). This study reveals that ARs contribute 30–60% of the annual precipitation in EA with maximum in summer and minimum in winter. The seasonal evolution of AR activities follows the northward march of the EA monsoon rainband from spring to early summer, then is decoupled from it in fall and winter.