Oceanic Microstructure Measurements by BAKLAN and GRIF

Abstract

The authors describe instruments and their calibration techniques developed at the Atlantic Branch of the P. P. Shizshov Institute of Oceanology, Russian Academy of Sciences and used for microstructure measurements by Russian oceanographers during the last decade. The vertical profiler BAKLAN and the towing body GRIF carried among other sensors a new microconductivity capillary probe with spectral resolution O(100 cpm). This sensor was used to calculate the scalar dissipation rate ? with noise level of 3 ? 10?10 K2 s?1. The kinetic energy dissipation rate ε was measured by an airfoil-type sensor with a noise level less than 8 ? 10?10 W kg?1. Results of the measurements are illustrated by the data obtained near the California coast and in the western equatorial Pacific. A parameterization of equatorial turbulence in terms of turbulent diffusivities and the gradient Richardson numbers is considered. A relationship between horizontal patchiness of conductivity microstructure in the coastal zone and local thermohaline fronts was detected.