Assessing Long-Term Changes in Sea Surface Temperature Extremes

Abstract:

Increasing ocean temperatures are expected to have substantial impacts on marine ecosystems. Although sea surface temperature changes in the mean have been widely studied, there is limited information on sea surface temperature extremes globally. Here we aim to identify regions undergoing critical change in sea surface temperature extremes. The generalized extreme value distribution is used to model annual maximum sea surface temperature and assess the presence of trends at the global scale. We investigate whether trends in sea surface temperature extremes arise from a shift in the distribution mean (change in location parameter) and/or increased variability (change in scale parameter). Regions that experience the largest trends in extremes are situated at high latitudes and those originate from both changes in location and scale of the distribution. The inclusion of the Arctic Oscillation as a covariate in the location and scale parameter captures some variability for high latitude regions. These results suggest that high-latitude regions should be monitored closely as they are undergoing rapid changes in sea surface temperature extremes.