An ocean perspective on CMIP6 climate model evaluations

This paper serves as an introduction to the Deep-Sea Research II special issue entitled an ocean perspective on CMIP6 model evaluations, which reported the progress of CMIP6 (Coupled Model Intercomparison Project phase 6) emphasizing the ocean component. The six papers in this volume provided a series of evaluations, including ENSO (El Nino-Southern Oscillation) phase locking, Ningaloo Nino, global marine heat waves, freshwater flux-induced stratification over the central tropical Pacific, global sea levels, and AMOC (Atlantic meridional overturning circulation). To complement the papers in this volume and to present a general view of the performance of CMIP6 models in simulating sea surface temperature (SST) and sea surface salinity (SSS), the historical simulation biases from 48 and 46 CMIP6 models compared with observations are analyzed, respectively. Although not able to cover all the major aspects of model evaluation, this special issue has provided crucial information for model development and research based on climate models.