1. The acc and Primary production in the southern ocean
James Fiorendino

2. Antarctic Circumpolar Current (ACC)
Driven by westerly winds
Isotherms and Isohalines contribute to eastward flow
3 – 9 cms m above bottom in Drake Passage
Bottom topography results in curvature of current due to conservation of potential vorticity

3. Antarctic Fronts
3 major fronts: Subtropical, polar, Southern (Antarctic Divergence)
Antarctic polar front (convergence) occurs at ~55° S and forms northern boundary of acc
Polar easterlies drive westward current close to the continent
Coriolis results in divergence
Fronts Account for 75% of transport by ACC

4. Antarctic convergence and divergence
North Atlantic deep water upwells at the Antarctic divergence
Upwelled water is high in nutrients, influences biology
Antarctic surface water sinks beneath warmer subantarctic water, becomes Antarctic intermediate water

5. Primary production in the southern ocean
Southern ocean is a high- nutrient low-chlorophyll area
Iron limits phytoplankton growth
Primary production is highest at fronts, coastal/shelf regions, and areas of ice retreat

6. Primary production in the southern ocean
Interaction of current with topography results in mixing at fronts
Cross-frontal mixing may provide limiting nutrients
Coastal regions and islands are a source of iron
Melting stabilizes water layer and release nutrients collected from the air

7. Sources
Knauss, J.A Introduction to Physical Oceanography. Waveland Press, Inc. Long Grove, IL.
Moore, J.K. and M.R. Abbott Phytoplankton chlorophyll distributions and primary production in the Southern Ocean. Journal of Geophysical Research, 105: 28,709 – 28,722
Klinck, L. and Nowlin, W.D. Jr Southern Ocean-Antarctic Circumpolar Current. In: Encyclopedia of Oceanography. Academic Press.
Raymont, J.E.G Plankton and Productivity in the Oceans 2nd Edition, Vol. 1. Pergamon Press. Elmsford, NY.
Moore, J.K., Abbott, M.R., and J.G. Richman Location and dynamics of the Antarctic Polar Front from satellite sea surface temperature data. Journal of Geophysical Research 104: 3059 – 3073.