文章基本信息

标题：Consistent biases in Antarctic sea ice concentration simulated by climate models
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作者：Lettie A. Roach ; Samuel M. Dean ; James A. Renwick 等
期刊名称：The Cryosphere
印刷版ISSN：1994-0416
电子版ISSN：1994-0424
出版年度：2018
卷号：12
期号：1
页码：365-383
DOI：10.5194/tc-12-365-2018
出版社：Copernicus Publications
摘要：The simulation of Antarctic sea ice in global climate models often does not agree with observations. In this study, we examine the compactness of sea ice, as well as the regional distribution of sea ice concentration, in climate models from the latest Coupled Model Intercomparison Project (CMIP5) and in satellite observations. We find substantial differences in concentration values between different sets of satellite observations, particularly at high concentrations, requiring careful treatment when comparing to models. As a fraction of total sea ice extent, models simulate too much loose, low-concentration sea ice cover throughout the year, and too little compact, high-concentration cover in the summer. In spite of the differences in physics between models, these tendencies are broadly consistent across the population of 40 CMIP5 simulations, a result not previously highlighted. Separating models with and without an explicit lateral melt term, we find that inclusion of lateral melt may account for overestimation of low-concentration cover. Targeted model experiments with a coupled ocean–sea ice model show that choice of constant floe diameter in the lateral melt scheme can also impact representation of loose ice. This suggests that current sea ice thermodynamics contribute to the inadequate simulation of the low-concentration regime in many models.