Circulation of the Turkish Straits System under interannual atmospheric forcing

A simulation of the Turkish Straits System
(TSS) using a high-resolution, three-dimensional, unstructured
mesh ocean circulation model with realistic atmospheric
forcing for the 2008–2013 period is presented. The
depth of the pycnocline between the upper and lower layers
remains stationary after 6 years of integration, indicating
that despite the limitations of the modelling system, the
simulation maintains its realism. The solutions capture important
responses to high-frequency atmospheric events such
as the reversal of the upper layer flow in the Bosphorus due
to southerly severe storms, i.e. blocking events, to the extent
that such storms are present in the forcing dataset. The
annual average circulations show two distinct patterns in the
Sea of Marmara. When the wind stress maximum is localised
in the central basin, the Bosphorus jet flows to the south and
turns west after reaching the Bozburun Peninsula. In contrast,
when the wind stress maximum increases and expands
in the north–south direction, the jet deviates to the west before
reaching the southern coast and forms a cyclonic gyre
in the central basin. In certain years, the mean kinetic energy
in the northern Sea of Marmara is found to be comparable to
that of the Bosphorus inflow.