EES 717: Earth System Science II
Evaluation II – May 04, 2012
Take Home Evaluation – Due Friday, May 18, 2012
Ocean Circulation
This is a take home evaluation. You can use all available materials that we discussed in
class, and discuss your answers with others if you wish. We do however request (and
expect) that the written short answers are your own INDIVIDUAL work. Please answer
as succinctly as possible (We have a very low tolerance for male cow fecal material).
The evaluation consists of 9 short answer questions, questions 1 through 8 are worth 10
points each, question 9 is worth 20 points.
1. Explain/define Thermo-Haline Circulation, (be sure to mention the driving
mechanisms for upwelling and downwelling of water involved in THC and rates
of transport where appropriate).
2. Explain/define Meridional Overturning Circulation, (be sure to mention how
MOC relates to THC, includes rates of transport where appropriate).
3. In general explain hysteresis behavior in a system and how modeling experiments
are conducted to generate the various shapes of hysteresis curves.
4. Explain the freshwater hysteresis in the context of MOC and how it relates to the
salinity feedback.
5. Explain steric and dynamic sea level changes in the context of the MOC.
Considering the 7%exp, what steric and dynamic sea level changes would be
expected for the east coast of the US?
6. Explain what effect the potential melting of the Greenland Ice Sheet will have on
MOC. Are the effects sensitive to the timing and distribution of the meltwater and
what is expected for future summer and winter sea ice coverage?
7. Explain the warm and cold pathways of the MOC in the South Atlantic.
8. What is the annual variability in the magnitude of the Benguela Current and how
do the warm and cold pathways influence the transport of heat to the North
Atlantic?
9. Explain Figure 1, be sure to discuss a) what controls Agulhas leakage, b) how
Agulhas leakage influences the AMOC and the salinity feedback, and c) its
relation to subsequent glacial and interglacial periods.
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If you use figures in your answers, please include the figure. Remember that
explanations with clear diagrams save a lot of words!
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