A numerical model of mixing and convection driven by surface buoyancy flux
Citable URI
https://hdl.handle.net/1912/5387DOI
10.1575/1912/5387Keyword
Ocean circulationAbstract
This thesis studies mixing and convection in a rectangular basin driven by a specified
heat flux at the surface. A numerical model is constructed for this purpose. The main
focus of the study is on the density and circulation structure resulting from the thermal
forcing.
In chapter two, a simple vertical one-dimensional model is developed to examine
the mixing processes under a given surface heat flux. In order to simulate strong vertical
mixing in the region where stratification is unstable, turbulent processes are modeled
by a convective overturning parameterization of eddy viscosity and diffusivity. The
results show that the density structure is strongly affected by the convective overturning
adjustment as surface cooling prevails, and the resulting density field is nearly depth
independent.
In chapter three, a more complicated two-dimensional model is constructed to
simulate mixing and circulation in a vertical rectangular basin with rigid boundaries.
The aspect ratio of the basin ranges from 1 to 0.001 and Rayleigh number from 104 to
2 x 1012. It is found that the circulation pattern is dominated by these two important
numbers. The roles of density overturning and density-momentum overturning mixing
are further investigated. The results show that the convective overturning not only
homogenizes the density field in the unstably stratified region but also contributes to
increase the circulation. A crude scale analysis of the system shows that the characteristics
of the density and momentum fields from the analysis agree well with the
numerical results.
Description
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1989
Collections
Suggested Citation
Thesis: Wang, Xiaoming, "A numerical model of mixing and convection driven by surface buoyancy flux", 1989-09, DOI:10.1575/1912/5387, https://hdl.handle.net/1912/5387Related items
Showing items related by title, author, creator and subject.
-
Seismic constraints on shallow crustal processes at the East Pacific Rise
Christeson, Gail L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-02)This thesis is concerned with understanding how oceanic crust is emplaced at mid-ocean ridges. The emphasis is upon fast-spreading ridges, and the use of seismic techniques to image the uppermost several hundred meters ... -
When an eddy encounters shelf-slope topography
Cherian, Deepak A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2016-09)Eddies in the ocean move westwards. Those shed by western boundary currents must then interact with continental shelf-slope topography at the western boundary. The presence of other eddies and mean lows complicates this ... -
Biological-physical interactions on Georges Bank : plankton transport and population dynamics of the ocean quahog, Arctica islandica
Lewis, Craig V. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1997-06)Advective losses of bank water during winter because of strong wind forcing were hypothesized to be a significant factor limiting recruitment of Georges Bank cormnunities. This hypothesis was examined using biological-physical ...