Geophysical Research Letters (Aug 2025)

Impacts of Indo‐Pacific Sea Surface Temperature Versus Internal Atmospheric Variability on the South China Sea Summer Monsoon

  • Marvin Xiang Ce Seow,
  • Bo Qiu,
  • Jianping Gan

DOI
https://doi.org/10.1029/2025gl117215
Journal volume & issue
Vol. 52, no. 16
pp. n/a – n/a

Abstract

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Abstract The South China Sea (SCS) summer (i.e., June–August [JJA]) monsoon experiences strong interannual variability, which is modulated by the western North Pacific subtropical high (WNPSH). Large‐scale steady‐state atmospheric circulations linked to JJA mean Indian Ocean basin and preceding winter–spring (i.e., January–March [JFM]) and JJA mean central Pacific sea surface temperatures (SSTs), as well as internal atmospheric variability, influence the SCS summer monsoon and WNPSH. We compare relative impacts of Indo‐Pacific SST and internal atmospheric variability on SCS summer monsoon and WNPSH interannual variabilities. Our results show that internal atmospheric variability is more important than any SST predictor in influencing the SCS summer monsoon and WNPSH variabilities. Also, JFM and JJA mean central Pacific SSTs control the SCS summer monsoon more than JJA mean Indian Ocean basin SST.

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