Abstract. The Sea of Azov is a small, shallow, and freshened sea
that receives a large freshwater discharge. Under certain external forcing
conditions low-salinity waters from the Sea of Azov flow into the north-eastern
part of the Black Sea through the narrow Kerch Strait and form a
surface-advected buoyant plume. Water flow in the Kerch Strait also
regularly occurs in the opposite direction, which results in the spreading of a
bottom-advected plume of saline and dense waters from the Black Sea into the
Sea of Azov. In this study we focus on the physical mechanisms that govern water
exchange through the Kerch Strait and analyse the dependence of its direction and
intensity on external forcing conditions. Analysis of satellite imagery,
wind data, and numerical modelling shows that water exchange in the Kerch
Strait is governed by a wind-induced barotropic pressure gradient. Water
flow through the shallow and narrow Kerch Strait is a one-way process for
the majority of the time. Outflow from the Sea of Azov to the Black Sea is
induced by moderate and strong north-easterly winds, while flow into the Sea
of Azov from the Black Sea occurs during wind relaxation periods. The direction
and intensity of water exchange have wind-governed synoptic and seasonal
variability, and they do not depend on the rate of river discharge to
the Sea of Azov on an intra-annual timescale. The analysed data reveal
dependencies between wind forcing conditions and spatial characteristics of
the buoyant plume formed by the outflow from the Sea of Azov.
Upwelling in the Kerch Strait and the Adjacent Waters of the Black Sea Based on the Contact and Satellite Data