Sub-mesoscale Wind-Front Interactions: the combined impact of thermal
and current feedback
Abstract
Surface ocean temperature and velocity anomalies at meso- and
sub-meso-scales induce wind stress anomalies. These wind-front
interactions, referred to as thermal (TFB) and current (CFB) feedbacks,
respectively, have been studied in isolation at mesoscale, yet they have
rarely been considered in tandem. Here, we assess the combined influence
of TFB and CFB and their relative impact on surface wind stress
derivatives. Analyses are based on output from two regions of the
Southern Ocean in a 4-6 km-resolution coupled simulation. Considering
both TFB and CFB shows regimes of interference, which remain mostly
linear down to the simulation resolution. The jointly-generated wind
stress curl anomalies approach 10-5 N-3, ~20 times
stronger than at mesoscale. The synergy of both feedbacks improves the
ability to reconstruct wind stress curl magnitude and structure from
both surface vorticity and SST gradients by 12-37% on average, compared
with using either one alone.