Sea level rise, surface warming, and the weakened buffering ability of South China Sea to strong typhoons in recent decades

• Published in: Scientific reports Vol. 7; no. 1; pp. 7418 - 9
• Main Authors: Sun, Jingru, Oey, Leo, Xu, F.-H., Lin, Y.-C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.08.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 704/106; 704/829; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Sea level; Storms; South China Sea
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-07572-3

Each year, a number of typhoons in the western North Pacific pass through the Luzon Strait into South China Sea (SCS). Although the storms remain above a warm open sea, the majority of them weaken due to atmospheric and oceanic environments unfavorable for typhoon intensification in SCS, which therefore serves as a natural buffer that shields the surrounding coasts from potentially more powerful storms. This study examines how this buffer has changed over inter-decadal and longer time scales. We show that the buffer weakens (i.e. greater potential for more powerful typhoons) in negative Pacific Decadal Oscillation (PDO) years, as well as with sea-level-rise and surface warming, caused primarily by the deepening of the ocean’s 26 °C isotherm Z 26 . A new Intensity Change Index is proposed to describe the typhoon intensity change as a function of Z 26 and other environmental variables. In SCS, the new index accounts for as high as 75% of the total variance of typhoon intensity change.