Pacific Marine Heatwaves in a Changing Climate 

Marine heatwaves in the ocean are characterized by large areas of extreme high temperature waters that can last from months to several years, like in the case of the 2013-2015 Northeast Pacific “Warm Blob”. The ecological and societal impacts of marine heatwave (MHW) is severe and includes the die-off of marine mammals and seabirds, the closure of fisheries, enhanced harmful algal blooms and other disruptions of ecosystem services. Although the MHW are considered extremes events, their evolution is connected to large-scale low-frequency dynamics of Pacific climate. In this talk, I will use a Linear Inverse Modeling (LIM) approach to diagnose how the coupling between the North Pacific and the El Niño Southern Oscillation (ENSO) in the tropics play a key role in the duration and spatial evolution of the MHW like the 2014-15. I will also use the LIM to develop a null-hypothesis of current ocean climate conditions and explore how the statistics of MHW are changing under anthropogenic forcing.