Marine Heatwaves over East Asian Marginal Seas Driven by Two Pacific Ocean Modes

Stott et al (2016) show that climate change has led to an increase in the frequency and intensity of daily temperature extremes. Extreme weathers such as cold surge and heatwave have more impact. There have been many studies about atmospheric heatwaves for several decades. However, studies on marine heatwaves (MHW), indicates the extremely warm sea surface temperature event occurring from several days up to several weeks, have been recently started and focused on case study in Australia and Europe.

In this study, we investigate the long-term variation of MHW and large-scale MHW processes in East Asian Marginal Seas (EAMS). Empirical Orthogonal Function (EOF) is investigated to analyze the component of MHW. The EOF1 exhibits one sign over the entire region and the EOF2 shows a see-saw pattern in around of Korea. Based on regression analysis between principal component (PC) of EOF and atmosphere/ocean variation, two different modes of MHW over EAMS are found. First mode is associated with Western pacific (WP) warming mode which is related to El Niño-Southern Oscillation. Second mode is accompanied with WP cooling mode which is explained by the large-scale anomalous anticyclone over East Asian region.