Major climate drivers of East Asian marine heatwaves

This study shows climate drivers responsible for East Asian marine heatwaves by Empirical Orthogonal Function analysis of marine heatwave duration and the relevant atmospheric and ocean fields. Here, long-term variability of marine heatwave frequency, duration, and intensity over East Asia Marginal Sea is constructed based on satellite sea surface temperature dataset from 1982 to 2018. The first process slowly warms the East Asian seas from the previous winter through summer due to the persistence of the Western North Pacific-to-East Asia anticyclonic circulation. The second process abruptly heated the East Asian seas during summer due to the extreme strengthening of the zonal anticyclonic circulation. Finally, we suggest major climate drivers of these two (fast versus slow) marine heatwave processes through global-scale ocean-atmosphere teleconnection processes with the subtropical western North Pacific convection, during the transition of El Nino to La Nina, and in zonal wave train in the Eurasian continent. This study provides the first insight to mechanisms of marine heatwaves over the western Pacific basin.