Orographically Anchored El Nino Effect on Summer Rainfall in Central China

TitleOrographically Anchored El Nino Effect on Summer Rainfall in Central China
Publication TypeJournal Article
Year of Publication2017
AuthorsHu KM, Xie SP, Huang G
JournalJournal of Climate
Date Published2017/12
Type of ArticleArticle
ISBN Number0894-8755
Accession NumberWOS:000423492500014
Keywordsanticyclone; boreal summer; enso; indian-ocean; Meteorology & Atmospheric Sciences; monsoon; northwest pacific; part i; sst anomalies; teleconnection; variability

Year-to-year variations in summer precipitation have great socioeconomic impacts on China. Historical rainfall variability over China is investigated using a newly released high-resolution dataset. The results reveal summer-mean rainfall anomalies associated with ENSO that are anchored by mountains in central China east of the Tibetan Plateau. These orographically anchored hot spots of ENSO influence are poorly represented in coarse-resolution datasets so far in use. In post-El Nino summers, an anomalous anticyclone forms over the tropical northwest Pacific, and the anomalous southwesterlies on the northwest flank cause rainfall to increase in mountainous central China through orographic lift. At upper levels, the winds induce additional adiabatic updraft by increasing the eastward advection of warm air from Tibet. In post-El Nino summers, large-scale moisture convergence induces rainfall anomalies elsewhere over flat eastern China, which move northward from June to August and amount to little in the seasonal mean.

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