Associate Professor
PhD, 2000, Columbia University
Biogeochemical Cycles Research Group
Research Interests
With training in oceanography and geochemistry, I conduct research on carbon cycle and climate change. In recent years, my focus has been on the global ocean and Lake Superior, which both comprise a complex natural network involving mechanisms of fluid interaction, biogeochemistry, and chemical exchange. Upper circulation is strongly influenced by winds. Deep circulation is driven in part by density gradients that arise from variations of water temperature and salt content. Both are influenced on large scales by Coriolis forces. Vertical mixing can bring nutrients from the deep to the near surface where plant and animal life can flourish. Cold surface waters at the two poles soak up more CO2 from the atmosphere than warm waters elsewhere. These processes are represented in numerical models of the earth system, global ocean, and Lake Superior. My research group tries to characterize the biogeochemical controls of air-sea CO2 exchange and carbon distribution within the ocean both at the present time and times of ice age climate. We also study Lake Superior, the largest lake in the world by surface area. It is undergoing significant change, with ice out days coming earlier and summertime surface waters becoming warmer. My group is focused on the relationship between wintertime lake ice and the lake-wide carbon cycle and the role of thermal bars (progressive seasonal warming from the shores to open waters) in controlling lake biogeochemistry and higher trophic level ecosystem.
Courses Taught
- Oceanography
- Earth Surface Dynamics
- Science and Politics of Global Warming
- Biogeochemical Cycles in the Ocean
- Graduate seminars
Selected Publications
- Matsumoto, K., K. Tokos, M. O. Chikamoto, and A. Ridgwell, Characterizing postindustrial changes in the oean carbon cycle in an Earth system model, Tellus, 62B, 296-313, 2010.
- Sun, X. and K. Matsumoto, Effects of sea ice on atmospheric pCO2: A revised view and implications for glacial and future climates, J. Geophysical Research, 115, G02015, doi:10.1029/2009JG001023, 2010.
- Archer, D., M. Eby, V. Brovkin, A. Ridgwell, L. Cao, U. Mikolajewicz, K. Caldeira, K. Matsumoto, G. Munhoven, A. Montenegro, and K. Tokos, Atmospheric lifetime of fossil fuel carbon dioxide, Annual Review of Earth and Planetary Sciences, 37, 117-134, 2009.
- Chikamoto, M., K. Matsumoto, and A. Ridgwell, Response of deep-sea CaCO3 sedimentation to Atlantic meridional overturning circulation shutdown, J. Geophysical Research, 113, G03017, doi:10.1029/2007JG000669, 2008.
- Nusbaumer, J. and K. Matsumoto, Climate and carbon cycle changes under the overshoot scenario, Global and Planetary Change, 62, 164-172, 2008.
- Matsumoto, K., Biology-mediated temperature control on atmospheric pCO2 and ocean biogeochemistry, Geophysical Research Letters, 34, L20605, doi:10.1029/2007GL031301, 2007.
- Matsumoto, K., Radiocarbon-based circulation age of the world oceans, J. Geophysical Research, 112, C09004, doi:10.1029/2007JC004095, 2007.
- Contributing author to Jansen, E., J. Overpeck, and others, Paleoclimate, Chapter 6 inClimate Change 2007: The Physical Science Basis. Contribution of WG1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by S. Solomon and others. Cambridge University Press, Cambridge, United Kingdom and New York, USA, 2007.
- Matsumoto, K. and N. Gruber, How accurate is the estimation of anthropogenic carbon in the ocean? An evaluation of the DC* method, Global Biogeochemical Cycles, 19, GB3014, doi:10.1029/2004GB002397, 2005.
- Matsumoto, K. and 35 others, Evaluation of ocean carbon cycle models with data-based metrics, Geophysical Research Letters, 31, L07303, doi:10.1029/2003GL018970, 2004.
- Matsumoto, K., J.L. Sarmiento, and M.A. Brzezinski, Silicic acid "leakage" from the Southern Ocean: A possible explanation for glacial atmospheric pCO2, Global Biogeochemical Cycles, 16(3), 10.1029/2001GB001442, 2002.
Recent Research Support
- NSF: REU: Fluids in the earth from surface to the core
- NSF: Collaborative research: The role of ice in the response of large lakes to a changing climate
- DOE: Changes in the natural ocean carbon cycle during the Industrial period
Recent Honors and Awards
- University of Minnesota McKnight Land-Grant Professorship, 2008-2010
- Swiss NSF Visiting Researcher Fellowship, 2005
- Geochemical Society of Japan Young Scientist Award, 2004