FIO‐ESM Version 2.0: Model Description and Evaluation

The First Institute of Oceanography Earth System Model (FIO‐ESM) version 2.0 was developed and participated in the Climate Model Intercomparison Project phase 6 (CMIP6). In comparison with FIO‐ESM v1.0, all component models of FIO‐ESM v2.0 are updated, and their resolutions are fined. In addition to the non‐breaking surface wave‐induced mixing (Bv), which has also been included in FIO‐ESM v1.0, there are three more distinctive physical processes in FIO‐ESM v2.0, including the effect of surface wave Stokes drifts on air–sea momentum and heat fluxes, the effect of wave‐induced sea spray on air–sea heat fluxes and the effect of sea surface temperature (SST) diurnal cycle on air–sea heat and gas fluxes. The FIO‐ESM v2.0 has conducted the CMIP6 Diagnostic, Evaluation, and Characterization of Klima (DECK) and historical experiments. The historical simulation of FIO‐ESM v2.0 for 1850–2014 is evaluated, including the surface air temperature (SAT), precipitation, SST, Atlantic Meridional Overturning Circulation (AMOC), El Niño‐Southern Oscillation (ENSO), and so forth. The climate changes with respect to SAT and SST global warming and decreasing AMOC are well reproduced by FIO‐ESM v2.0. The correlation coefficient of the global annual mean SAT anomaly can reach 0.92 with observations. In particular, the large warm SST bias at the east coast of tropical Pacific from FIO‐ESM v1.0, which is a common challenge for all climate models, is dramatically reduced in FIO‐ESM v2.0 and the ENSO period within the range of 2–7 years is well reproduced with the largest variation of SST anomalies occurring in boreal winter, which is consistent with observations. Plain Language Summary As the climate changing, climate models are core tools for understanding the mechanisms underlying these changes and predicting future trends. Although tremendous efforts have been made, there are still large common biases for most climate models. In this paper, for the first time, we introduced the effects of surface wave Stokes drift and sea spray on air–sea momentum and heat fluxes into a climate model. Moreover, the diurnal cycle of sea surface temperature on air–sea heat and gas fluxes is introduced through parameterization. A new climate model of the FIO‐ESM v2.0 was successfully developed, and the model biases were considerably reduced compared with that of the previous version. Key Points The effects of wave‐induced Stokes drifts and sea spray on air–sea momentum and heat fluxes are firstly co