THE CHARACTERISTICS OF SUMMER PERSISTENT RAINFALL OVER YANGTZE-HUAIHE RIVER VALLEY AND ITS RELATIONSHIP WITH THE EAST ASIAN JET STREAMS
YAN Pei-wen
HUANG Dan-qing
Abstract：Based on the summer persistent rainfall over the Yangtze-Huaihe River Basin (YHRB) during 1960-2011,the characteristics of both the individual-station-based and regional persistent rainfall and the relationship between the East Asian jet streams are investigated in this study.With focus on the long-duration precipitation (4d and above),the results indicate that the frequency has increased and the impact stations have expanded in recent years.Both the concurrent variation of the EASJ and the East Asian Polar Front jet stream (EAPJ) have contributed to the first two modes of EOF.Associated with the polar-ward (equator-ward) shift of the EAPJ (EASJ),the cold-dry air and warm-humid air may converge over YHRB and easily trigger the long-persistent precipitation.For the EOF2,the strengthened EAPJ and weakened EASJ may result in the southern-flood-northern-drought precipitation anomaly,via the water vapor and ascending motion.We further investigate the longer regional persistent precipitation.Nearly 7 days precedent of the precipitation onset,the EAPJ and EASJ significantly enhance,particularly for the EAPJ.Consequently,the persistent western Pacific subtropical high and north wind anomalies may benefit the warm-humid and cold-dry air activities,and therefore sustain the precipitation.
Keywords：climatologypersistent rainfallEast Asian Jet Streamcold-warm air
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 741-749 )