Storms can have a direct impact on sea ice, but whether their effect is
seen weeks to months later has received little attention. The immediate
and longer term impacts of an idealized open water wind storm are
investigated with a one-dimensional coupled ice-ocean model. Storms with
different momentum, duration and date of occurrence are tested. During
the storm, the mechanical forcing causes a deepening of the mixed layer,
leading to an increase in mixed layer heat content, despite a decrease
in mixed layer temperature. This results in a delay in sea ice formation
that ranges between a few hours to weeks compared to the control run,
depending on the storm characteristics. Throughout the freezing period,
the storm-induced thick mixed layer experiences little variability,
preventing warm water entrainment at the base of the mixed layer. This
leads to faster sea ice growth compared to the control run, resulting in
sea ice thickness differences of a few millimeters to around 10 cm
before the melting onset. These results are stronger for runs with
higher momentum storms which cause greater mixed layer deepening. Storms
occurring in early August, when the ocean surface heat flux is positive,
also amplify the results by forcing a greater increase in mixed layer
heat content. The impacts of the storms are sensitive to the initial
stratification, and amplified for a highly stratified ocean. We suggest
that localized storms could significantly influence the seasonal
dynamics of the mixed layer and consequently impact sea ice conditions.