PH waters remained hot even after El Niño ended in May 2024 - UP study 

Record-high sea surface temperatures (SST) in the Philippines were recorded for three months even after the El Niño phenomenon ended in May 2024, a study by marine scientists from the University of the Philippines said. 

Researchers from UP Marine Science Institute said the elevated SSTs persisted from June to August last year. They noted that SST peaked at 30.45°C in June 2024, which is higher than the record-high daily SST of 29.6°C in November 2023 and 30.0°C in May 2024.

“This implies that the maximum daily SST (30.45°C) in the Philippines during the same El Niño event is much higher than the global daily SST (21.09°C) reported, which poses greater threat to temperature-sensitive marine organisms in the Philippines,” the study read. 

“It is also worthy to note that these maximum daily SSTs occur at different months demonstrating that the global pattern of SST variations is very distinct from that of the Philippines,” it added. 

The state weather bureau PAGASA first declared the start of El Niño in July 2023.  

The El Niño phenomenon is characterized by the abnormal warming of sea surface temperature in the central and eastern equatorial Pacific Ocean leading to below normal rainfall.

More than 4 million people or some 1 million families in various regions were affected by the extreme heat. 

The scientists said marine heatwaves or “prolonged, anomalously warm water events” that have had an impact on marine environments likely occurred during the recent El Niño event. In the study, they grouped the marine heatwaves (MHW) they identified into two. 

“The first group of MHW anomalies occurred at the middle of the El Niño event from November 2023 to January 2024, but more importantly during the northeast monsoon season when SSTs are expected to be much lower throughout the year, especially north and northwest of the Philippines,” the study read. “This explains why MHW anomalies first appeared northwest of the Philippines even if SSTs at this location from November 2023-January 2024 are much lower than other parts of the country.” 

“The second group of MHW anomalies started from April-August 2024. This group shows the combined effects of El Niño and the seasonal southwest monsoon on the intensity and spatial distribution of MHW anomalies during and even after the 2023-2024 El Niño event,” the study further read. 

According to the scientists, while El Niño was ending then, warm winds brought by the southwest monsoon (habagat) intensified the heat. Hence, this prolonged the marine heatwaves in the country even after the El Niño was over. 

“Warm SSTs remnant of the preceding El Niño event which ended in May 2024 were enhanced by the seasonal southwest monsoon which brings warm, moist air to the Philippines from June to September. This explains the continuous occurrence of MHW anomalies throughout the country even after the El Niño event,” the study read. 

Further, the combined effects of El Niño and local seasonal monsoon patterns can alter the temperature of marine ecosystems in the country. 

“This may lead to modified breeding, migration, and feeding patterns of various marine species,” the scientists said.

In a report released last June, the World Meteorological Organization (WMO) noted the unprecedented parade of 6 typhoons that battered the Philippines in four weeks from October to November 2024, saying "persistently high ocean heat content in the Philippine sea from mid-April 2024 created ideal conditions for tropical cyclone development."

In a statement, Dr. Charina Lyn Amedo-Repollo, Assistant Professor and Physical Oceanographer at the Marine Science Institute - University of the Philippines Diliman said "these ocean extremes are alarming indicators of the escalating climate crisis and underscore the Philippines’ high vulnerability." — Vince Angelo Ferreras/LA, GMA Integrated News