We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Summer Regional Daily‐Precipitation Extreme Events in Huang‐Huai Rivers Region of China and Their Relationships With Rossby Wave Packet Activities.
- Authors
Sun, Siyuan; Guan, Zhaoyong; Ye, Dechao
- Abstract
The regional daily‐precipitation extreme events (RDPEs) have profound societal impacts. Based on NCEP/NCAR reanalysis and datasets of daily basic meteorological elements from China national meteorological stations, the statistical characteristics of RDPEs in the Huang‐Huai Rivers (HHR) region in eastern China from 1979 to 2016 and their relationships with Rossby wave activities are investigated. The results show that in the summers (June‐August) of 1979–2016, the 95 percentile threshold of regional extreme daily‐precipitation in HHR region is 27.32 mm/d. There are 77 RDPEs in total in the past 38 years. When RDPEs occur, HHR region is controlled by an anomalous cyclonic circulation in the middle and lower troposphere and an anomalous anticyclonic circulation in the upper troposphere. The water vapor is mainly transported from the Bay of Bengal and the South China Sea into HHR region. Rossby waves originate near the Caspian Sea and obviously disperse downstream‐ward, taking about 4 days to move to HHR region. The eddy kinetic energy at 200 hPa over HHR region reaches its maximum on the day before RDPEs occur and decrease from then on. This decrease is dominated by processes including advection transport of eddy kinetic energy and barotropic energy conversion by time‐mean flow. The intensification tendency of baroclinic conversion weakens while barotropic conversion play an important role in the weakening of eddy kinetic energy. The migrations of wave packets, meridional transports of warmer air and momentum over HHR region during 4 days before RDPEs occurrences may provide useful clues to forecasting RDPEs. Key Points: Rossby waves disperse downstream‐ward from the Caspian Sea to HHR region and make the downstream development of disturbances possibleEddy kinetic energy at 200 hPa over HHR region reaches its maximum on the day before RDPEs occur and rapidly decreases when RDPEs occurWarmer air meridional transports to HHR region during 4 days before RDPEs occur, while eddy momentum fluxes to the pole decrease rapidly
- Subjects
CHINA; METEOROLOGICAL precipitation; METEOROLOGICAL stations; TROPOSPHERE; WAVE packets; BAROCLINICITY; RIVERS
- Publication
Journal of Geophysical Research. Atmospheres, 2021, Vol 126, Issue 7, p1
- ISSN
2169-897X
- Publication type
Article
- DOI
10.1029/2020JD034065