Fall 2007 Geology & Geophysics 8980 Section 4
Instructor: Katsumi Matsumoto
Pillsbury Hall 212
katsumi@umn.edu
Office Hours: By appointment
Class Hours: Tuesdays at 1-2 PM in Pillsbury Hall 121
First, organizational meeting on 9/11
Class Format: A class participant will lead a discussion of the assigned reading in the first 30-40 minutes of a 60-minute class time. With the remaining time, Matsumoto will preview the topic for the following week.
Grading (1 credit): Pass/fail based on class attendance and participation
In this seminar, we will read seminal and recent papers on important topics in physical and biogeochemical oceanography and global carbon cycle. This semester, we will cover meridional overturning circulation, mesoscale eddies, observational constraints on the global carbon budget, and a couple chapters from the most recent IPCC report AR4. This seminar is intended to familiarize students in biogeochemistry, oceanography, limnology, and paleoclimatology to important concepts that form the foundation of oceanography and global carbon cycle. We will tend to read concept papers more than technical papers.
Weekly Schedule
Week 1 (week of 9/4) – Organizational meeting
Sign up for papers
Week 2 (week of 9/11) – A driver of deep ocean circulation
Is the deep ocean circulation driven by “push” by surface density forcing?
[Broecker, 1991]
Week 3 (week of 9/18) – Alternate driver of deep ocean circulation
The deep ocean circulation may instead be driven by “pull” by winds and tidal mixing
[Ledwell et al., 2000; Toggweiler, 1994; Wunsch, 2002]
Week 4 (week of 9/25) – Surface return flow of the global meridional overturning circulation
Which upper ocean flows combine with deep circulation to complete the loop?
[Gordon, 1986]
Week 5 (week of 10/2) – Antarctic Bottom Water
The formation of Antarctic Bottom Water involves the so-called “shelf” processes
[Foster and Carmack, 1976]
Week 6 (week of 10/9) – Observational constraints on global ocean circulation
What do hydrographic data from World Ocean Circulation Experiment tell us?
[Ganachaud and Wunsch, 2000]
Week 7 (week of 10/16) – The deep ocean on the global carbon cycle
The transport and ventilation of the deep water are key to long term global carbon cycle
[Broecker and Peng, 1992; Sarmiento and Toggweiler, 1984]
Week 8 (week of 10/23) – Mesoscale eddies
Are subtropical gyres really deserts in terms of biological productivity?
[McGillicudy et al., 1998; Oschlies and Garcon, 1998]
Week 9 (week of 10/30) – Transport model and sea surface pCO2 on global carbon budget
A first definitive response to the “missing sink”
[Tans et al., 1990]
Week 10 (week of 11/6) – No class (Matsumoto is away)
Week 11 (week of 11/13) – Atmospheric oxygen measurements
What does change in atmospheric O2 tell us about the global carbon cycle?
[Keeling et al., 1996; Keeling and Shertz, 1992]
Week 12 (week of 11/20) – Thanksgiving (no class)
Week 13 (week of 11/27) – Anthropogenic carbon cycle
Where has fossil fuel CO2 gone in the past and where is it going in the future?
[Sarmiento and Gruber, 2002]
Week 14 (week of 12/4) – Oceanic climate change
Observed oceanic climate changes summarized by IPCC AR4
[Bindoff et al., 2007]
Week 15 (week of 12/11) – Global warming and IPCC
Modeling of global warming by Hansen the guru and IPCC’s historical overview of the topic
[Hansen et al., 2005; Somerville et al., 2007]
Reading list and references
Bindoff, N. L., J. Willebrand, V. Artale, A. Cazenave, J. Gregory, S. Gulev, K. Hanawa, C. Le Quere, S. Levitus, Y. Nojiri, C. K. Shum, L. Talley, and A. Unnikrishnan, Observations: Oceanic climate change and sea level. in Climate change 2007: The physical science basis. Contribution of Working Group I to the Fourth Asessment Report of the Intergovernmental Panel of Climate Change, edited by Solomon, S., D. Qin, M. R. Manning, Z. Chen, M. Marquis, K. B. Averyt, et al., Cambridge University Press, Cambridge, 2007.
Broecker, W. S., The great ocean conveyor, Oceanography, 4, 79-90, 1991.
Broecker, W. S., and T.-H. Peng, Interhemispheric transport of carbon dioxide by ocean circulation, Nature, 356, 587-589, 1992.
Foster, T. D., and E. C. Carmack, Frontal zone mixing and Antarctic bottom water formation in the southern Weddell Sea, Deep-Sea Research, 23, 301-317, 1976.
Ganachaud, A., and C. Wunsch, Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data, Nature, 408, 453-457, 2000.
Gordon, A. L., Interocean exchange of thermocline water, J. Geophys. Res., 91, 5037-5046, 1986.
Hansen, J., L. Nazarenko, R. Ruedy, M. Sato, J. Willis, A. Del Genio, D. Koch, A. Lacis, K. Lo, S. Menon, T. Novakov, J. Perlwitz, G. Russell, G. A. Schmidt, and N. Tausnev, Earth's energy imbalance: Confirmation and implications, Science, 308, 1431-1435, 2005.
Keeling, R. F., S. C. Piper, and M. Heimann, Global and hemispheric CO2 sinks deduced from changes in atmospheric O2 concentration, Nature, 381, 218-221, 1996.
Keeling, R. F., and S. R. Shertz, Seasonal and interannual variations in atmospheric oxygen and implications for the global carbon cycle, Nature, 358, 723-727, 1992.
Ledwell, J. R., E. T. Montgomery, K. L. Polzin, L. C. St. Laurent, R. W. Schmitt, and J. Toole, Evidence for enhanced mixing over rough topography in the abyssal ocean, Nature, 403, 179-182, 2000.
McGillicudy, D. J., A. R. Robinson, D. A. Siegel, H. W. Jannasch, R. Johnson, T. Dickey, J. McNeil, A. F. Michaels, and A. H. Knap, Influence of mesoscale eddies on new production in the Sargasso Sea, Nature, 394, 263-266, 1998.
Oschlies, A., and V. Garcon, Eddy-induced enhancement of primary production in a model of the North Atlantic Ocean, Nature, 394, 266-269, 1998.
Sarmiento, J. L., and N. Gruber, Sinks for anthropogenic carbon, Physics Today, August, 30-36, 2002.
Sarmiento, J. L., and J. R. Toggweiler, A new model for the role of the oceans in determining atmospheric pCO2, Nature, 308, 621-624, 1984.
Somerville, R., H. Le Treut, U. Cubasch, Y. Ding, C. Mauritzen, A. Mokssit, T. Peterson, and M. Prather, Historical overview of climate change. in Climate change 2007: The physical science basis. Contribution of Working Group I to the Fourth Asessment Report of the Intergovernmental Panel of Climate Change, edited by Solomon, S., D. Qin, M. R. Manning, Z. Chen, M. Marquis, K. B. Averyt, et al., Cambridge University Press, Cambridge, 2007.
Tans, P. P., I. Y. Fung, and T. Takahashi, Observational constraints on the global atmospheric CO2 budget, Science, 247, 1431-1438, 1990.
Toggweiler, J. R., The ocean's overturning circulation, Physics Today, November 1994, 45-50, 1994.
Wunsch, C., What is the thermohaline circulation?, Science, 298, 1179-1181, 2002.