Advantages of the latest Los Alamos Sea-Ice Model (CICE): evaluation of the simulated spatiotemporal variation of Arctic sea ice

Abstract

The Los Alamos Sea-Ice Model (CICE) is one of the most popular sea-ice models. All versions of it have been the main sea-ice module coupled to climate system models. Therefore, evaluating their simulation capability is an important step in developing climate system models. Compared with observations and previous versions (CICE4.0 and CICE5.0), the advantages of CICE6.0 (the latest version) are analyzed in this paper. It is found that CICE6.0 has the minimum interannual errors, and the seasonal cycle it simulates is the most consistent with observations. CICE4.0 overestimates winter sea-ice and underestimates summer sea-ice severely. Meanwhile, the errors of CICE5.0 in winter are larger than for the other versions. The main attention is paid to the perennial ice and the seasonal ice. The spatial distribution of root-mean-square errors indicates that the simulated errors are distributed in the Atlantic sector and the outer Arctic. Both CICE4.0 and CICE5.0 underestimate the concentration of the perennial ice and overestimate that of the seasonal ice in these areas. Meanwhile, CICE6.0 solves this problem commendably. Moreover, the decadal trends it simulates are comparatively the best, especially in the central Arctic sea. The other versions underestimate the decadal trend of the perennial ice and overestimate that of the seasonal ice. In addition, an index used to objectively describe the difference in the spatial distribution between the simulation and observation shows that CICE6.0 produces the best simulated spatial distribution.

Keywords

• los alamos sea-ice model (cice)
• spatiotemporal variation
• perennial ice
• seasonal ice
• model evaluation