Northeast Pacific marine heatwaves linked to Kuroshio Extension variability

Abstract

Abstract Marine heatwave events in the Northeast Pacific Ocean from 2013-2015 and 2019-2020 have had significant impacts on ocean life and livelihoods in the region. Numerous studies have linked these marine heatwaves to known modes of climate variability. Here we show that the observed evolution of the 2013-2015 Northeast Pacific marine heatwave best correlates with the evolution of historical sea surface temperatures in response to variations in the Kuroshio Extension. By using ocean and atmospheric reanalysis data from 1981-2020 and ocean nutrient data from 1993-2020 from an ocean biogeochemistry model, we further report the physical and biogeochemical changes during this heat event and their relation to these same Kuroshio variations. Using these results, we propose an atmospheric teleconnection between Kuroshio Extension variations and Marine Heatwaves in the Northeast Pacific. This teleconnection’s influence further extends to the marine biogeochemistry and productivity in the Northeast Pacific region via Kuroshio-influenced modifications to mixed layer thickness.