Precipitation Characteristics related to Atmospheric Rivers in East Asia
Abstract
Atmospheric rivers (ARs) play a critical role in the poleward transport of atmospheric water vapor in the midlatitudes. ARs are also a great concern in the occurrence of hydrologic extremes and water resources in coastal regions as intense water vapor fluxes associated with an AR often cause heavy precipitation and flooding in regions of AR landfall. Previous studies show that a number of flooding events in the Pacific coast of the United States and the Atlantic coasts of Western Europe are related to AR landfalls. Large impacts of AR landfalls on the occurrence of extreme hydrologic events and their role in global water cycle have made ARs among the topics of intense research in recent years; however, studies focusing on ARs in East Asia remain limited.
This study analyzes the climatology of ARs and AR-related precipitation characteristics and their regional variations in East Asia (EA) using an AR chronology constructed based on the vertically-integrated water vapor transport in the atmosphere in conjunction with a globally consistent detection algorithm that facilitates comparison with ARs in other regions. This study has found that the East Asian coastal regions including the Korean Peninsula, western Japan and southern and east-central China are among the most prominent AR hot spots in the world in boreal summer. AR activity decreases rapidly away from the midlatitude coastal region towards inland and higher/lower-latitude regions. AR landfalls are clearly related to heavier-than-normal mean rainfall intensity. This translates to the highest occurrence of heavy precipitation events in southern Korea and Japan within EA. In southern China, AR effects on heavier-than-normal precipitation intensity are limited to low and intermediate intensity events; unlike in southern Korea/Japan, heaviest rainfall events in the southern China coastal region occur in non-AR rainfall events. The intraseasonal variations of the AR effects on the summer precipitation in EA and the North Pacific appear to be closely correlated with the northward march of the main rainband over EA and the North Pacific for spring and early summer. Acknowledgements This study was supported by the NIMS/KMA under NIMS-2016-3100.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A33S3091K
- Keywords:
-
- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3319 General circulation;
- ATMOSPHERIC PROCESSES;
- 3337 Global climate models;
- ATMOSPHERIC PROCESSES;
- 3373 Tropical dynamics;
- ATMOSPHERIC PROCESSES