Journal of Oceanography

, Volume 71, Issue 1, pp 77–90 | Cite as

Climatology of hot events in the western equatorial Pacific

  • Anindya Wirasatriya
  • Hiroshi Kawamura
  • Teruhisa Shimada
  • Kohtaro Hosoda
Original Article

Abstract

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.

Keywords

High SST Hot event Merged SST Western Pacific warm pool 

Abbreviations

SST

Sea surface temperature

HE

Hot event

NGSST-O-Global-V2.0a

New Generation Sea Surface Temperature version 2.0a

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Copyright information

© The Oceanographic Society of Japan and Springer Japan 2014

Authors and Affiliations

  • Anindya Wirasatriya
    • 1
  • Hiroshi Kawamura
    • 1
  • Teruhisa Shimada
    • 1
  • Kohtaro Hosoda
    • 1
  1. 1.Center for Atmospheric and Oceanic Studies, Graduate School of ScienceTohoku UniversitySendaiJapan

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