The structure of thermohaline and bio-optical fields in the surface layer of the Kara Sea in September 2011

Abstract

We present data of measurements of thermohaline and bio-optical fields in the surface layer of the Kara Sea carried out in September 2012, during the 59th cruise of the R.V Akademik Mstislav Keldysh. Measurements were performed during vessel motion along the expedition route using a pump-through CTD system (temperature and salinity) and UV fluorescent lidar (concentrations of chlorophyll, total suspended matter, and dissolved organic matter) with a high spatial resolution (about 10–100 m). Detailed sea-area distribution maps of the above parameters are presented, frontal zones are detected, T,S diagrams for the surface water layer are constructed, and basic water types are identified. It is shown that Ob–Yenisei freshwater runoff is a main factor affecting properties of the surface layer. In the second part of this paper, a numerical model of the dynamics of continental runoff in the Kara Sea is suggested. Model experiments were carried out under real wind conditions of August–September 2011 (NCAR/NCEP reanalysis); the model was validated on the basis of in situ data collected during the cruise.