Back to notes for Lectures 18 to 20
Mixed layers and upper ocean temperature and salinity distribution - Emery, Talley and Pickard sections 4.2 - 4.2.4; 4.3.1; 4.4
Upper ocean processes: Tomczak and Godfrey
Mode waters: Hanawa and Talley (see electronic reserves)
Subtropical underwater (salinity maximum): Worthington (1976) monograph on N. Atlantic circulation (see electronic reserves)
1. What processes can cause a surface layer to mix?
2. Suppose that a surface layer has been mixed to about 50 meters. Suppose that the forcing (wind, cooling, etc.) has stopped. Suppose that the sun is shining and that there is net heat going into the ocean. Sketch (schematic) how the ocean will restratify over the course of the heating period. Ignore the diurnal (daily) cycle.
3. Suppose you accidentally drop a very large shipload of a very rare and non-biogenic chemical in the middle of the North Atlantic, at about 22N and 20W. Explain where you might find the chemical about 5 years later, assuming there is no mixing in the vertical or horizontal.
4. Suppose you dump the same chemical in the subpolar region around 50N and 10W. Where might you find this chemical about 5 years later?
5. What is Subtropical Mode Water, where is it found, and what is a possible mechanism for forming it?
6. Same question for Central Water.
7. Explain the competing arguments for creation and maintenance of the ocean's main pycnocline.
9. If you dump the same chemical (questions 3 and 4) in the mid-winter in the southern ocean just north of the Subantarctic Front and south of Australia (say around 100 E), where might you find this chemical 1 month later? (consider its vertical extent first). What water mass have you dumped it into? Where might you find this chemical 5 to 10 years later?
10. What evidence is there for large-scale vertical mixing between the surface/intermediate/deep layers?
11. Why does water flow from the Pacific to the Indian Ocean? How might you recognize the Pacific water in the Indian Ocean?
12. Where are the two locations where water passes between the Pacific and Indian Oceans?
Gordon, A.L., 1986. Interocean exchange of thermocline water. J. Geophys. Res., 91, 5037-5046.
Gordon, A.L. and T. N. Baker, 1986. Southern Ocean Atlas, International Decade of Ocean Exploration, Amerind Publishing.
Hanawa, K. and L. D. Talley, 2001. Mode Waters. In Ocean Circulation
Large, W. G., J. C. McWilliams and S. C. Doney, 1994. OCeanic vertical mixing: a review and amodel with a nonlocal boundary layer parameterization. Rev. Geophys. 32, 363-404.
Legg, S. and J. C. McWilliams, 2002. J. Phys. Oceanogr.
Rintoul, S., 1991. South Atlantic Interbasin exchange. J. Geophys. Res., 96, 2675-2692.
Wust, G., 1935. The stratosphere of the Atlantic Ocean. Translated by W.J. Emery, Amerind, 1978.
Wyrtki, K., 1971. Oceanographic Atlas of the International Indian Ocean Expedition. National Science Foundation, lots of pages.