Detection of hot event in the equatorial Indo-Pacific warm pool using advanced satellite sea surface temperature, solar radiation, and wind speed

Using advance satellite-derived sea surface temperature (SST), solar radiation and wind speed products, we investigate hot events (HEs) associated with very high SST of around 30°C. Amplitude of the SST diurnal variation (DSST) is obtained by an empirical formula with the downward surface shortwave radiation (DSSR) and the wind speed. The HE is defined as a connected region with SST > the time-dependent SST threshold of about 30°C having a minimum areal size greater than 3 × 10⁶ km² and lasting for a period longer than 10 days. Thirty-one hot events were detected from 1993 to 2003 in and around the equatorial Indo-Pacific warm pool. The HE precursor is increase of an area with SST > the time-dependent SST threshold, and the HE starts when the areal size exceeds the areal threshold. It keeps the very high SST for a while, and then its SST decreases with decrease of the HE area toward its ending phase. The HE area and the high-DSST area correspond with each other on timescales of daily and the whole one event period. In the HE period, a clear-sky and low-wind condition becomes the reason for large DSST appearance. Through statistics of the detected 31 HEs, it is indicated that the mean HE period, the mean areal size, and the means of the regional HE areal averaged SST are 24.2 days, 1.57 × 10⁷ km², and 0.25°C above the time-dependent SST threshold, respectively. The HE area shifts with season though they stay within/around the SST contour of 28°C in the Indo-Pacific oceans.