Evaluation of surface meteorology parameters and heat fluxes from CFSR and ERA5 over the Pacific Arctic Region

Abstract Surface meteorological parameters and heat fluxes play a crucial role in air–sea (ice) interactions. In this study, the accuracy of surface meteorological parameters and air–sea heat flux data obtained from the Climate Forecast System Reanalysis (CFSR) and the fifth‐generation European Center for Medium‐range Weather Forecasts Reanalysis (ERA5) over the Pacific Arctic Region were evaluated. Data from two buoys and 11 cruises provided by the Chinese Arctic Research Expedition were used in this evaluation. The observational data were independent of the reanalysis products. In open water, the meteorological data from CFSR and ERA5 corresponded reasonably well with the observational data. However, the heat flux data from both CFSR and ERA5 showed poor accuracy, especially for shortwave radiation. Buoy data showed that the Bering Sea has changed from absorbing heat from the atmosphere to releasing heat into the atmosphere in mid‐September. Both CFSR and ERA5 could accurately simulate the timing of this directional shift in the net heat flux over the Bering Sea surface. In general, CFSR overestimated and ERA5 underestimated the net heat flux over the Bering Sea surface. In the ice region, ERA5 overestimated the meteorological parameters. The bias of ERA5 meteorological parameters is less affected by changes in sea ice concentration than that of CFSR. In addition, we found that the parameterization scheme was not the dominant cause of the discrepancies in the turbulent heat flux data from the buoys and reanalysis products. Among the meteorological parameters, for both ERA5 and CFSR versus the buoy, air temperature and specific humidity error were the largest sources of discrepancy for sensible heat flux and latent heat flux respectively.