Climatology of hot events in the western equatorial Pacific

Anindya Wirasatriya, Hiroshi Kawamura, Teruhisa Shimada, Kohtaro Hosoda

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8 Citations (Scopus)


We investigated the climatology of hot events (HEs) in the western equatorial Pacific. HEs are characterized by well-organized high sea surface temperatures (SSTs). We proposed a method for identifying HEs using a space–time-dependent threshold with a minimum areal size of 2 × 106 km2, and with a duration (period) of >6 days. We thus identified 71 HEs from the optimally interpolated SST dataset during 2003–2011. Their mean duration, areal size, and amplitude were 18.14 days, 6.30 × 106 km2, and 0.33 °C, respectively. On average, the HEs developed more slowly than they decayed. They were distributed within the equatorial band to the subtropical Pacific (20°S–30°N), with an eastward extension to 150°W. In particular, the HEs occurred most frequently along the northern coasts of New Guinea and the Solomon Islands to 180°E. Seasonal variation in the HE distribution was observed: a northward shift during boreal summer and a southward shift during boreal winter. The distribution of HE occurrences corresponded to the climatological SST of the western Pacific warm pool. HEs occurred under conditions of low wind speeds (~2.56 m/s) and high levels of solar radiation (~225 W/m2). However, since the high levels of solar radiation occurred over the entire area of the western equatorial Pacific during HE periods, the low wind speed distribution became a key factor in the occurrence of HEs in the western equatorial Pacific. Seasonal shifts in wind speed and solar radiation were found to influence the seasonal shift in HE distribution.

Original languageEnglish
Pages (from-to)77-90
Number of pages14
JournalJournal of Oceanography
Issue number1
Publication statusPublished - 2015 Feb


  • High SST
  • Hot event
  • Merged SST
  • Western Pacific warm pool

ASJC Scopus subject areas

  • Oceanography


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