2 edition of Measurements of a barotropic planetary vorticity mode in an eddy-resolving quasi-geostrophic model using acoustic tomography found in the catalog.
Available from National Technical Information Service, Springfield, Va.ADA205409.Thesis (M.S. in Ocean Engineering) Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution, Aug. 1988.Includes bibliographical references.
|The Physical Object|
|Pagination||xvi, 65 p. :|
|Number of Pages||84|
nodata File Size: 5MB.
Exchange of Notes Relating to the Tax Convention with Kazakhstan, Treaty Document 104-15, U.S. Senate, 104th Congress, First Session.
The second question addressed is: which component of the flow is the most important in data assimilation to drive the model response towards a baseline reference ocean? When the entire basin is considered, the wave activity is generated near the surface and bottom, and is dissipated in the interior.
If only the depth-averaged flow is known, a decrease in the horizontal resolution of data assimilation has an immediate effect: the r. The PE model is used in a spin-down mode and initialized with an analytic jet profile with geostrophically balanced fields. Baroclinic waves of various scale heights appear to contribute to the wave activity and its fluxes, depending on the location. The knowledge of the interior density field is much more effective in decreasing the root-mean-square r.
Two major questions are addressed in the present study. This process is new to oceanographers, who only now are on the verge of having available world-wide synoptic maps of dynamic variables. In the assimilation of the barotropic flow alone, even with dense resolution, the errors in the deep layers always show an increasing trend. We specifically compare the knowledge of the depth-integrated flow only, corresponding to measurements of the total transport, with the knowledge of the density field only, or equivalently the velocity shear.
The stress exerted by the wind on the surface of the sea is a force per unit area of the surface and it couples downward into the water column through frictional forces so that the horizontal momentum is transferred vertically. The wind-driven circulation is the result of a chain of indirect processes working on the entire bulk of the fluid than the direct effects of the stress acting on the surface layers.
Large-scale structures of quasi-geostrophic transient wave activity and its fluxes in the North Atlantic are studied using 8-year daily mean output of a quasi-global eddy-resolving model. errors sharply increase and the assimilation run diverges from the reference ocean.
A geostrophically balanced initialization is sufficient to ensure smooth jet evolutions, with no apparent gravity waves, over long time durations in the spin-down mode. Substantial wave energy emanates from the Gulf Stream in the thermocline and from the eastern North Atlantic in the upper deep layers.
Also, wave generation in the middle latitudes is found in the vicinity of zero lines of the mean meridional potential vorticity gradient. At the same time, there are clear signs of wave generation in the open ocean and where strong currents flow over topographic features. If the baroclinic structure is known, coarse horizontal resolutions of data insertion can be reached before significantly worsening the model estimates.
The results show an extremely large range in the wave activity and its fluxes. Thus, the surface stress put into the water by the wind is transformed by friction into a body stress throughout a surface boundary layer known as the Ekman layer, with the induced subsurface horizontal flow called Ekman flow.
Large-scale dynamics of the main oceanic gyres must be understood in terms of several subtle and pervasive forces, such as Ekman boundary layer transport and downwelling or upwelling, Sverdrup interior transport, conservation of potential vorticity, frictional western boundary currents, geostrophic balance, and quasi-geostrophic meandering. This chapter discusses geophysical fluid dynamics with an emphasis on the dynamics of wave currents and wave circulation.
Large-scale dynamics of the main oceanic gyres must be understood in terms of several subtle and pervasive forces, such as Ekman boundary layer transport and downwelling or upwelling, Sverdrup interior transport, conservation of potential vorticity, frictional western boundary currents, geostrophic balance, and quasi-geostrophic meandering.
errors relative to the reference ocean.
No sophisticated initialization procedures seem, therefore, to be required.