Interannual variation of the late spring-early summer monsoon rainfall in the northern part of the South China Sea

Tsing Chang Chen, Wan Ru Huang, Ming Cheng Yen

    Research output: Contribution to journalArticlepeer-review

    20 Citations (Scopus)

    Abstract

    Major rainfall (≥60%) in the northern part of the South China Sea (between North Vietnam and Taiwan) during May-June (the mei-yu season-the first phase of the Southeast-East Asian monsoon) is produced by rainstorms originating over the northern Vietnam-southwestern China region and the northern part of the South China Sea. As observed in this study, the occurrence frequency of rainstorms and rainfall contribution by these rainstorms undergoes a distinct interannual variation, in-phase with those of monsoon westerlies in northern Indochina and sea surface temperature (SST) anomalies over the NOAA Niño-3.4 region ΔSST (Niño-3.4). This in-phase relationship between monsoon westerlies and the DSST (Niño-3.4) anomalies is a result of the filling (deepening) of the subtropical Asian continental thermal low in response to the ΔSST (Niño-3.4) warm (cold) anomalies. Accompanied with this response is a slight southward (northward) shift of the North Pacific convergence zone (NPCZ), which extends from southern China to the North Pacific east of Japan. Thus, a favorable environment that meets the Charney-Stern instability criterion in initiating rainstorm genesis is enhanced (suppressed) by the intensification (weakening) of the monsoon shear flow formed by the midtropospheric northwesterly flow around the northeast periphery of the Tibetan Plateau and the monsoon westerlies. The meridional shift of the NPCZ established an elongated anomalous convergence (divergence) zone of water vapor flux along rainstorm tracks to increase (reduce) the rain-producing efficiency of rainstorms. Consequently, this interannual rainfall variation between northern Vietnam and Taiwan is primarily caused by rainstorm genesis and rain-producing efficiency.

    Original languageEnglish
    Pages (from-to)4295-4313
    Number of pages19
    JournalJournal of Climate
    Volume24
    Issue number16
    DOIs
    Publication statusPublished - 2011 Aug

    Keywords

    • Asia
    • Interannual variability
    • Monsoons
    • Rainfall
    • Summer/warm season

    ASJC Scopus subject areas

    • Atmospheric Science

    Fingerprint Dive into the research topics of 'Interannual variation of the late spring-early summer monsoon rainfall in the northern part of the South China Sea'. Together they form a unique fingerprint.

    Cite this