WCD-07. An Optimal Precursor of Northeast Pacific Marine Heatwaves and Central Pacific El Niño events

The intensity of Northeast Pacific marine heatwaves (MHWs) has been related to local stochastic atmospheric forcing with limited predictability, but their evolution and persistence may be controlled by large-scale climate influences. A Linear Inverse Model (LIM) containing both sea surface temperature and sea surface height (SSH) anomalies is used to identify the “optimal” conditions for observed Northeast Pacific MHW events that developed two-to-four seasons later. These optimal initial conditions include SSH anomalies that are responsible for most of the MHW growth, suggesting the relevance of subsurface ocean dynamics. Moreover, Northeast Pacific MHW growth occurs as part of a basin-scale dynamical mode that links the North Pacific to central equatorial Pacific El Niño events, whose subsequent development may lengthen MHW duration.