SIO 210: Introduction to Physical Oceanography

Study guide: Wind forced circulation - N. Atlantic, S. Atlantic, S. Pacific, Indian and Southern Oceans

Back to notes for N. Atlantic and southern hemisphere

Reading (read one on each ocean carefully, skim the others):

Atlantic - Tomczak and Godfrey, pp. 253-259, 263-272, and chapter 15
Atlantic - Pickard and Emery, sections 7.34, 7.35; (skim 7.41, 7.44, 7.45)
Indian, Southern - Pickard and Emery, sections 7.32, 7.63, 7.65, 7.7, 7.8

Atlantic - Tomczak and Godfrey, pp. 253-259, 263-272, and chapter 15
Indian, Southern - Tomczak and Godfrey, chapters 6, 11 (pp 193-195, 198-201, 208-220), 12

Other reading:
Reid, J.L., 1994. On the total geostrophic circulation of the North Atlantic Ocean: flow patterns, tracers and transports. Progr. in Oceanogr., 33, 1-92.
Reid, J.L., 1997: On the total geostrophic circulation of the Pacific Ocean. Flow patterns, tracers and transports. Progr. Oceanogr., 39, 263-352.
Reid, J. L., 2003: On the total geostrophic circulation of the Indian Ocean. Flow patterns, tracers and transports. Progr. Oceanogr.

Study questions - southern hemisphere

2. Explain why the subtropical gyre has two different western boundary currents.

3. Explain why the subpolar gyre has two different western boundary currents.

4. Where is the Azores Current?

5. The subpolar gyre circulation is more complicated than the N. Pacific's subpolar gyre circulation. This gets into a later lecture, but can you surmise why the surface currents of the N. Atlantic subpolar gyre flow to the northeast and up to the area west of Norway, while the deeper flow in the N. Atlantic subpolar gyre just follows along the bathymetry in a cyclonic pattern?

Southern hemisphere
1. Are there subpolar (cyclonic) wind-driven "gyres" in the southern hemisphere?

2. Why are the properties in the three southern hemisphere oceans fairly similar compared with those in the northern hemisphere?

3. What distinguishes the Antarctic Circumpolar Current from all of the other strong (non-equatorial) currents?

4. What are the major fronts of the Antarctic Circumpolar Current? How do you distinguish them from each other on a north-south transect across them?

5. The Leeuwin Current is said to "go the wrong way". Contrast it with the eastern boundary currents in the other 4 oceans. Why does it go the "wrong" way?

6. Where does upper ocean water pass from the Indian to the Atlantic Ocean? What current does it start in in the Indian Ocean? What current does it possibly join in the Atlantic Ocean? List another mechanism besides smoothly-joined currents that passes water from the Indian to the Atlantic.

7. Where are the two locations where water passes between the Pacific and Indian Oceans?

8. How and where does the Antarctic Circumpolar Current deviate from being exactly zonal (following a single latitude)? Where is it farthest north? Where is it farthest south?

Further reading and figure sources

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.

Mantyla, A.W. and J. L. Reid, 1995. On the origins of deep and bottom waters of the Indian Ocean. J. Geophys. Res., 100, 2417-2439.

Reid, J.L., 1981. On the mid-depth circulation of the World Ocean. In Evolution of Physical Oceanography, MIT Press, 70-111.

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.