Accession Number : ADA181991
Title : Importance of Rotation Shear Stress for Entrainment in the Ocean Mixed Layer.
Descriptive Note : Doctoral thesis,
Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA
Personal Author(s) : Gallacher,Patrick C
PDF Url : ADA181991
Report Date : Jun 1987
Pagination or Media Count : 143
Abstract : The interaction of the northward component of planetary rotation and the east-west Reynolds stress affects the isotropy of the integral scale turbulence in the upper ocean by redistributing turbulent kinetic energy (TKE) among the components. This 'rotation stress' mechanism is incorporated into a vertically integrated model of the ocean mixed layer. Simulations of Ocean Weather Stations P (50 N, 145 W) and N (30 N, 140 W) are used to compare this model with the Garwood (19777) model and with observations. The significant effect is the augmentation (for easterly winds) or reduction (for westerly winds( of the ratio of vertical to horizontal TKE. The rate of entrainment is affected by the change in the vertical convergence of TLE at the interface between the mixed layer and the pycnocline. Rotation stress significantly alters the mixing on diurnal to synoptic time scales during late winter and early spring. With rotation stress, retreat is 10-30% greater than without rotation stress. Typically, the ratio of vertical to total TKE is three times larger when rotation stress is included and the dissipation enhancement of Garwood (1977) is neglected. The resulting TKE distribution is more isotropic and in better agreement with laboratory results for neutrally stratified shear flows. This study demonstrates the need for measurements of the TKE budget in the upper ocean to confirm these findings and to further test the hypotheses of TKE models in oceanic applications. Keywords: Air Sea Interactions; Coriolis Effects; Turbulence and Mixing Processes; Upper Ocean Processes; Theses.
Descriptors : *TURBULENCE, *MIXED LAYER(MARINE), *SHEAR STRESSES, AIR WATER INTERACTIONS, DISSIPATION, OPTIMIZATION, EAST(DIRECTION), WIND, SCALE, PLANETS, ROTATION, CORIOLIS EFFECT, SPRING SEASON, HYPOTHESES, MIXING, OCEAN MODELS, ENTRAINMENT, RATES, EARTH(PLANET), MOMENTUM TRANSFER, ISOTROPISM, RATIOS, ROTATION, STRESSES, FLOW, STRATIFICATION, SHEAR PROPERTIES, OCEANS, INTEGRATED SYSTEMS, VERTICAL ORIENTATION, ROTATION, KINETIC ENERGY, CONVERGENCE, VERTICAL ORIENTATION, WINTER
Subject Categories : Physical and Dynamic Oceanography
Distribution Statement : APPROVED FOR PUBLIC RELEASE