Accession Number : ADA265961


Title :   Shear, Strain and Thermohaline Vertical Fine Structure in the Upper Ocean


Descriptive Note : Doctoral thesis


Corporate Author : SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB


Personal Author(s) : Anderson, Steven P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a265961.pdf


Report Date : Jan 1993


Pagination or Media Count : 155


Abstract : Observations of fine scale (1-100m) vertical shear, strain and thermohaline structure are interpreted in terms of internal wave and frontal zone dynamics. The date were collected with the Marine Physical Laboratory 161 kHz Doppler sonar and a pair of CTD's. The two systems were operated from R/P FLIP for 18 days during February-March, 1990, as part of the SWAPP (35 deg N, 127 deg W) experiment. These simultaneous measurements of velocity and density provide an unique opportunity to study the vertical advection of shear layers. The observed shear variance is dominated by near inertial waves, with 35 m vertical wavelengths. These inertial waves propagate down from the mixed layer and are vertically advected by higher frequency waves. Vertical wavenumber- frequency spectral of shear and strain are examined in Eulerian (fixed depth) and semi-Langrangian (isopyncal following) coordinates. The semi-Langrangian shear and strain variances are more consistent with variances modeled by a linear superposition of internal waves. The p.d.f.'s of buoyancy frequency and Froude number (buoyancy normalized shear) are determined using the kinematic strain model of Pinkel and Anderson (1992). The Froude number distribution shows good agreement with data presented here and historical data (PATCHEX; Kunze et al., 1990). The advection of a frontal zone past the experiment site yielded detailed observations of frontal interleaving. Two vertical interleaving scales am observed.


Descriptors :   *OCEAN WAVES , *DOPPLER SONAR , KINEMATICS , VELOCITY , FREQUENCY , DYNAMICS , DEPTH , COORDINATES , OCEANS , ADVECTION , FINES , FROUDE NUMBER , GEOPOTENTIAL , BUOYANCY , FRONTS(OCEANOGRAPHY) , INTERNAL WAVES , SONAR , SHEAR STRESSES , SPECTRA , STRAIN(MECHANICS) , MODELS , DENSITY , MEASUREMENT


Subject Categories : Physical and Dynamic Oceanography
      Acoustic Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE