Sea Ice Rheology Experiment (SIREx), Part II: Evaluating simulated
linear kinematic features in high-resolution sea-ice simulations
Abstract
Simulating sea-ice drift and deformation in the Arctic Ocean is still a
challenge because of the multi-scale interaction of sea-ice floes that
compose the Arctic sea ice cover. The Sea Ice Rheology Experiment
(SIREx) is a model intercomparison project formed within the Forum of
Arctic Modeling and Observational Synthesis (FAMOS) to collect and
design skill metrics to evaluate different recently suggested approaches
for modeling linear kinematic features (LKFs) and provide guidance for
modeling small-scale deformation. In this contribution, spatial and
temporal properties of LKFs are assessed in 36 simulations of
state-of-the-art sea ice models and compared to deformation features
derived from RADARSAT Geophysical Processor System (RGPS). All
simulations produce LKFs, but only very few models realistically
simulate at least some statistics of LKF properties such as densities,
lengths, or growth rates. All SIREx models overestimate the angle of
fracture between conjugate pairs of LKFs and LKF lifetimes pointing to
inaccurate model physics. The temporal and spatial resolution of a
simulation and the spatial resolution of atmospheric forcing affect
simulated LKFs as much as the model’s sea ice rheology and numerics.
Only in very high resolution simulations (≤2\,km) the
concentration and thickness anomalies along LKFs are large enough to
affect air-ice-ocean interaction processes.