Attribution of the 2015 record high sea surface temperatures over the central equatorial Pacific and tropical Indian Ocean. (21st April 2017)

• Record Type: Journal Article
• Authors: Park, In-Hong; Min, Seung-Ki; Yeh, Sang-Wook; Weller, Evan; Kim, Seon Tae
• Is Part Of: Environmental research letters. Volume 12:Number 4(2017:Apr.)
• Publication Date: 2017-04-21
• Subjects: attribution -- sea surface temperature -- central equatorial Pacific Ocean -- tropical Indian Ocean -- anthropogenic forcing; Environmental sciences -- Periodicals; Human ecology -- Research -- Periodicals; Environmental health -- Periodicals; 333.7
• DOI: 10.1088/1748-9326/aa678f
• Languages: English
• ISSNs: 1748-9326

Abstract

Abstract: This study assessed the anthropogenic contribution to the 2015 record-breaking high sea surface temperatures (SSTs) observed in the central equatorial Pacific and tropical Indian Ocean. Considering a close link between extreme warm events in these regions, we conducted a joint attribution analysis using a fraction of attributable risk approach. Probability of occurrence of such extreme anomalies and long-term trends for the two oceanic regions were compared between CMIP5 multi-model simulations with and without anthropogenic forcing. Results show that the excessive warming in both regions is well beyond the range of natural variability and robustly attributable to human activities due to greenhouse gas increase. We further explored associated mechanisms including the Bjerknes feedback and background anthropogenic warming. It is concluded that background warming was the main contribution to the 2015 extreme SST event over the central equatorial Pacific Ocean on a developing El Niño condition, which in turn induced the extreme SST event over the tropical Indian Ocean through the atmospheric bridge effect.