Development of Coupled Data Assimilation With the BCC Climate System Model: Highlighting the Role of Sea?Ice Assimilation for Global Analysis

The coupled data assimilation (CDA) system consisting of ocean, sea-ice, and atmosphere components with the Beijing Climate Center (BCC) System Model has been developed to provide reliable analyses atmosphere, sea-ice states. It incorporates ocean temperature/salinity profiles, sea surface temperature, level height, concentration observations at a daily frequency, reanalysis 6-hourly frequency. Results show that is capable realistically reproducing climatology variability atmosphere. performances in analyzing component are comparable those well-known reanalyses were once used initialize BCC model for climate predictions. A series experiments without CDA framework designed explore role (DA). addition DA exerts very small influence analysis upper temperature over Arctic area, but leads an evident reduction error 1000 m south 60°S. Particularly, only inclusion can make ocean/ocean-atmosphere effective providing skillful high-latitude Southern Ocean. Furthermore, we find on basis DA, improve tropical tropospheric along better mid- stratospheric These results address importance coordination CDA.