A Measurement of Nearshore Langmuir Circulation.

Abstract

An experiment was carried out to measure vertical velocities associated with Langmuir circulation in Monterey Bay, California. Areas of convergence and divergence marked by windrows were seeded with 20 micrometers diameter sand. Water samples collected with Nansen bottles were examined with a Coulter counter to determine sand distribution in the vertical columns. A mathematical formulation for the sand distribution was developed in which vertical velocity was entered as a parameter. Matching calculated and observed distributions then gave a value for the vertical velocity associated with the Langmuir circulation. The mathematical model assumes constant coefficients and sinking under the influence of buoyancy forces, vertical advection and diffusion. The Langmuir circulation showed a cellular pattern with vertical velocities if 2,2 cm/sec downward in the area of convergence and 0.8 cm/sec upward in the area of divergence at a wind speed of 6.0 m/sec. These results are in no way to be interpreted as conclusive; their importance lies in that they suggest that the technique described could be useful. Some of the difficulties with the experimental and theoretical methods are discussed.

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1975
Accession Number
ADA009071

Entities

People

  • Alexander Maratos
  • E. D. Traganza
  • J. A. Galt
  • Noel E. J. Boston

Organizations

  • Naval Postgraduate School

Tags

DTIC Thesaurus Topics

  • Advection
  • Buoyancy
  • California
  • Coefficients
  • Convergence
  • Diameters
  • Diffusion
  • Mathematical Models
  • Measurement
  • Measuring Instruments
  • Micrometers
  • Models
  • Physical Properties

Readers

  • Aerosol Science/Aerosol Physics
  • Atmospheric Science/Meteorology
  • Oceanography.