The frequency and duration of marine heatwaves (MHWs) have been increasing with ocean warming due to climate change. This study investigates the role of Arctic warming in the increase of Northeast Pacific MHW days during boreal summers using satellite data, reanalysis data, and idealized coupled model experiments. Results show that strong Arctic warming alters atmospheric circulation, reducing low-level cloud cover and increasing solar radiative heat fluxes, leading to higher sea surface temperatures and more MHW days. An idealized model experiment supports this hypothesis, highlighting the need to consider projected Arctic climate changes in climate adaptation and mitigation plans.

Se-Yong Song, Sang-Wook Yeh, Hyerim Kim, Neil J. Holbrook