Future projection of marine heat waves in a global marine hotspot Case of East/Japan Sea

Abstract

The future analysis of the Marine Heat Waves (MHWs) has high uncertainty due to the significant shortcomings of the Global Climate Models (GCMs) in simulating the Sea Surface Temperature (SST) and the MHWs. This study suggests a more systematic approach to do the future projection of MHWs. Our study area is East/Japan Sea which is a large marine ecosystem exposed to rapid warming of the ocean. This study found the models; ACCESS-CM2, BCC-CSM2-MR ACCESS-ESM1, and GFDL-ESM4 from Coupled Model Intercomparison Project sixth phase (CMIP6) are the best performing GCMs in the East Sea by analyzing their grid-wise performance during the historical period (1985–2014). Using the ensemble mean from the selected models, the future MHW metrices of frequency, maximum intensity, and duration during the near future (2041–2070) and far future (2071–2100) was investigated. Following the state-of-art, shifting baseline approach was utilized to identify the MHWs and 30 years were used as the climatology period for each historical and future periods. The time series results from the ensemble mean indicated that high emission scenarios (SSP3-7.0, and SSP5-8.5) would have higher trends than that of low emission scenarios (SSP1-2.6, and SSP2-4.5) as well as that of historical observations. The high emission scenarios would have lower values in the beginning of their respective climatology period when compared to that of low emission scenarios but rather higher values toward the end of the period. The average MHW metrices of near and far futures shows certain shifts compared to that of historical but the numerical values are almost similar to that of historical period.