Improving Arctic sea-ice thickness estimates with the assimilation of
CryoSat-2 summer observations
Abstract
Rapidly shrinking Arctic sea ice has had significant impacts on the
Arctic Ocean and many outer Arctic regions. It is therefore urgently
needed to reliably estimate Arctic sea-ice thickness (SIT) by combined
use of available observation and numerical modeling. Here, for the first
time, we assimilate the latest CryoSat-2 summer SIT data into a coupled
ice-ocean model. In particular, an Incremental Analysis Update scheme is
implemented to overcome the discontinuity brought by assimilating
biweekly SIT and daily sea ice concentration data. Along with an
improvement in sea ice volume, our SIT estimates have smaller errors
than that without SIT assimilation in areas where the sea ice is
roughest and experiences strong deformation, e.g., around the Fram
Strait and Greenland. This study suggests that the newly-developed
CryoSat-2 SIT product, when assimilated properly with our approach, has
great potential for Arctic sea ice simulation and prediction.