Accession Number:

ADA165250

Title:

A High-Resolution Cluster of Oceanographic Instruments for Boundary Layer Measurements under Ice.

Descriptive Note:

Final rept. 26 Sep 83-30 Nov 85 on Phase 2,

Corporate Author:

FLOW INDUSTRIES INC KENT WA

Personal Author(s):

Report Date:

1985-11-01

Pagination or Media Count:

101.0

Abstract:

Three high-resolution clusters HRCs of oceanographic instruments, each consisting of three diode laser Doppler velocimeters DLDVs, a high-frequency thermistor probe and an dual-electrode conductivity probe, have been developed for measurements of turbulent momentum, heat and mass fluxes in the oceanic boundary layer under ice. The spatial resolution was designed to be 2 cm or better. The DLDVs, which are the essential components of the HRCs, were first developed and successfully tested in the laboratory, then they were deployed during two field experiments. Two experimental units were deployed during the 1984 Marginal Ice Zone Experiment MIZEX 84, and two prototype velocity-temperature-conductivity clusters were deployed during the 1985 Arctic Internal Wave Experiment AIWEX 85. During MIZEX 84, velocity components were measured simultaneously with the DLDV and ducted current meters. Good agreement was generally observed. The AIWEX 85 results also included temperature and conductivity measurements. Variations in temperature and conductivity at depths of 2 and 4 m were only observed with one sensor to exceed 0.01 C and 10 micromhocm, respectively for a time scale up to one hour. This indicate that the boundary layer under the ice flow was essentially well-mixed, which is consistent with other observations during the same time period April and May 1985. Both field experiments showed adequacy of scattering particles for use with the DLDV. The spatial resolution of the DLDV, which was found to be proportional to the sampling rate, achieved the target value of 2 cm, at last one order of magnitude better than that attainable by mechanical current meters.

Subject Categories:

  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE