Assessment of Arctic Sea Ice and Surface Climate Conditions in Nine
CMIP6 Climate Models
Abstract
The observed retreat and anticipated further decline in Arctic sea ice
hold strong climate, environmental, and societal implications. In
predicting climate evolution, ensembles of coupled climate models have
demonstrated appreciable accuracy in simulating sea ice area and volume
trends throughout the historical period. However, individual climate
models still show significant differences in simulating the sea ice
thickness distribution. To better understand individual model
performance in sea ice simulation, nine climate models previously
identified to provide plausible sea ice decline and global temperature
change were evaluated in comparison with Arctic satellite and reanalysis
derived sea ice thickness data, sea ice extent records, and atmospheric
reanalysis data of surface wind and air temperature. Assessment found
that the simulated spatial distribution of historical sea ice thickness
varies greatly between models and that several key limitations persist
among models. Primarily, most models do not capture the thickest regimes
of multi-year ice present in the Wandel and Lincoln Seas; those that do,
often possess erroneous positive bias in other regions such as the
Laptev Sea or along the Eurasian Arctic Shelf. From analysis, no model
could be identified as performing best overall in simulating historic
sea ice, as model bias varies regionally and seasonally. Nonetheless,
the bias maps and statistical measures derived from this analysis should
enhance understanding of the limitations of each climate model. This
research is motivated in-part to inform future usage of coupled climate
model projection for regional modeling efforts and enhance climate
change preparedness and resilience in the Arctic.