Currents variability of the Kara sea

Abstract

To study the water dynamics of the Kara Sea in the prospective areas of shelf development, the instrumental measurements of currents speeds were made at 6 submerged autonomous buoy stations with about a year duration for 5 of them and about half a year duration for 1.

A spectral analysis of implementations of these measurements allowed to determine, that characteristic currents feature is a presence of annual, tidal and synoptical components of currents speeds variability. The contribution estimate of each of these components into the total process variance using the method of vector variance analysis was performed in the work.

Estimates of currents speeds show almost the same character of variability at all submerged autonomous buoy stations  by all parameters. It is appearing in the numerical values of main parameters of variability, profiles shape of their vertical distribution, evolution of these profiles in the annual course and in the correlations of summary current characteristic and its nonperiodical component. At all 6 submerged autonomous buoy stations  along all depths, mean currents are directed to N-NNE-NE and values of mean scalar speed of summary current and maximum at upper horizons are changing within relatively small limits of 10,5–1,5 cm/s and 65–80 cm/s correspondingly. For vertical distribution, it is typical a decrease with a depth the values of speeds and their variability when the direction of mean transfer and relative proximity to it of maximum variability direction is preserved. The annual course is well-defined and becomes apparent in increase of current speeds and their variability in case of simultaneous strengthening of vertical contrast in spring and summer. The variability of nonperiodical current at all depths and corresponding vertical contrasts are weakened in comparison with summary current and ellipses shape of standard drviation is more elongate.