On the Black Sea deepwater circulation features derived from numerical modeling and measurement data

The Black Sea deepwater currents below the main pycnocline at the depths more than 350 m are considered. Current velocities derived from different datasets are compared. Results of two numerical experiments with MHI non-linear z-coordinate ocean model, estimates of deep Argo float velocities, and in-situ data accumulated in MHI Database are analyzed. It is shown that sub-pycnocline velocities obtained by simulation with MHI model and SKIRON atmospheric forcing generally correlate with Lagrangian deep Argo velocity estimations and MHI Database mean velocities. Existence of deepwater cyclonic and anticyclonic vortexes is drawn from the datasets under consideration. The qualitative difference between modeling results and measurements is the narrow quasi-periodic currents along the northeast continental slope which are not succeeded to verify by available data of Argo and MHI Database collected so far.