High-resolution data on mesoscale dynamics of the Caspian Sea upper layer, obtained in a numerical reconstruction
The dataset contains information on the currents in the upper 15-meter layer of the Caspian Sea in 2003-2005. The velocity fields were reconstructed in an eddy-resolving ocean general circulation model SZ-COMPAS using a realistic forcing. The data arrays have a very high resolution: ~2 km in space and 4 hours in time. This is sufficient to resolve most of the mesoscale features of sea dynamics as well as a wide range of their temporal spectrum, including inertial oscillations, synoptic and seasonal variability. The NetCDF files are: 3 files with instantaneous currents and 3 files with monthly mean currents (suffix “mm” in the file names). Each file corresponds to one of the three horizons (depths): 1 m, 7 m, and 15 m. In the horizontal plane the data are defined on a uniform geographical grid (46.7625–54.2125°E, 36.5092–47.2892°N), dimensions of all of the arrays are 299 by 589. The period covered by the instantaneous data is 2003, time step is 4 hours; the first record corresponds to 2003-01-01 04:00:00 GMT. The period covered by the monthly mean data is 2003-2005 with one vector field for every month, defined on the last day of the month. All data dimension is cm/s. It should be noted that the model describes the upper 30-meter layer of the sea in sigma-coordinate, so the data values are actually defined on the 1st, 4th, and 8th sigma-horizons, rather than 1 m, 7 m, and 15 m depths. This means that, in the sea cells with bottom depth less than 30 m, the actual depth of the data nodes is ~3%, ~23% and 50% of real water column height, while in the rest of cells (with bottom depth greater than 30 m), the data nodes are located at ~1 m, ~7 m, and ~15 m of depth (± few centimeters depending on the local sea level).