Robert M. DeConto

Climatology - Paleoclimatology - Earth System Modeling

Chief Undergraduate Advisor: Earth Systems Program

Robert ("Rob") DeConto has been examining the physical and chemical coupling processes between individual climate system components, in an interdisciplinary "Earth system" approach to understanding global climate dynamics, and mechanisms of past, present, and future climatic change. Following are a few highlights of collaborative research projects presently underway.

The interactive coupling of GCMs to predictive vegetation/ecosystem models, allowing realistic feedback between terrestrial ecosystems and the atmosphere, is an exciting advance in the Earth system approach to global climate modeling. In one example, climate-vegetation simulations of the very warm, ice-free Cretaceous period (~100 Ma), illustrate the powerful controlling effect of terrestrial ecosystem distributions in the maintenance of continental equability during periods of extreme global warmth.

Rob has been working with Dr. Dave Pollard (Penn State), coupling dynamical ice-sheet models to GCMs, to examine the sensitivity of the coupled atmosphere-cryosphere system to changing external boundary conditions. They are currently applying their new modeling scheme to the glacial history of Antarctica and Greenland. The animation below shows a numerical model prediction of Early Oligocene ice sheets, responding to changing orbital parameters (DeConto and Pollard, 2003).

The recognition that numerical modeling studies like the one illustrated above, in combination with geological data gathering, will contribute to new advances in our understanding of Antarctic climate and ice sheet history, has led to a new international research inititiative call ACE (Antarctic Climate Evolution). The goal of ACE is to facilitate the study of Antarctic climate and glacial history, through paleoclimate and ice sheet modeling studies, purposefully integrated with geological investigations of the proxy record of ancient Antarctic climates and ice sheets. ACE is now a planning group. A proposal to make ACE an official SCAR program is in progress- and will be submitted in the coming year. A more complete introduction to ACE can be found at http://www.ace.scar.org

In the ocean realm, Rob has been working with scientists at NCAR, in the application of OGCMs to paleoclimate studies. This work has led to the recognition of likely changes in the partitioning of oceanic heat transport mechanisms through geologic time. Rob is also collaborating with researchers affiliated with JGOFS (Joint Global Ocean Flux Study). JGOFS goal is to better understand the marine carbon cycle and its role in past, present and future climate change.

Rob's climatic interests aren't restricted to the distant Geologic past. He has been studying land use and its role in climatic change over the past several centuries, and is currently working on a project aimed at understanding the connection between climate change and North Atlantic fish populations.

Courses Taught:

• Introductory Oceanography GEO 103
• Honors Introductory Oceanography GEOH02
• Oceans and Climate GEO 595D
• Pre-Quarternary Environmental Change
• Introduction to Climate/Environmental Modeling GEO 592C
• Paleoceanography GEO 592P
• The Science of Climate Change (New seminar, Fall, 2002)
• Independent study in Meteorology

Representative Publications:

• DeConto, R. M. and Pollard, D., 2003, Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2, Nature, v. 421, p. 245-249.
• Peter Barrett's News and Views relatated to the Cenozoic glaciation paper: Barrett, P., 2003, Cooling a continent, Nature, v. 421, p. 221-223.
• DeConto, R. M., and Pollard, D. (in press) A coupled climate-ice sheet modeling approach to the early Cenozoic history of the Antarctic ice sheet: Palaeogeography, Palaeoclimatology, Palaeoecology.
• Bergengren, J. C., Thompson, S. L., Pollard, D., and DeConto, R. M., 2001, Modeling global climate-vegetation interactions in a doubled CO2 world: Climatic Change 50, 31-74.
• Brady, E. C., DeConto, R. M., and Thompson, S. L., 1998, Deep water formation and poleward ocean heat transport in the warm climate extreme of the Cretaceous (80 Ma): Geophysical Research Letters, 25, 4205-4208.
• DeConto, R. M., Bergengren, J. C., Hay, W. W., 1998, Modeling Late Cretaceous climate and vegetation: Zentralblatt für Geologie und Paläontologie, Teil I, 1996, 11/12, 1433-1444.
• DeConto, R. M., Brady, E., Bergengren, J. C., Thompson, S. L., Pollard. D., Hay, W. W., 1999, Late Cretaceous climate, vegetation, and ocean interactions: in Huber, B., MacLeod, K. G, Wing, S. L (eds.) Warm Climates in Earth History, Cambridge University Press, p. 275-297.
• DeConto, R. M., Hay, W. W., Thompson, S. L., and Bergengren, J. C., 1999, Late Cretaceous climate and vegetation interactions: the cold continental interior paradox: in Barrera, E., and Johnson, C. (eds.), The Evolution of Cretaceous Ocean/Climate Systems, Geological Society of America Special Paper 332, p. 391-406.
• DeConto, R. M., Thompson, S. L., and Pollard, D., 1999, Recent advances in paleoclimate modeling: toward better simulations of warm paleoclimates: in Huber, B., MacLeod, K. G, Wing, S. L (eds.) Warm Climates in Earth History, Cambridge University Press, p. 21-49.
• Hay, W. W. and DeConto, R. M., 1999, A comparison of modern and Late Cretaceous meridional energy transport and oceanology: in Barrera, E., and Johnson, C. (eds.), The Evolution of Cretaceous Ocean/Climate Systems, Geological Society of America Special Paper 332..
• Hay, W.W., DeConto, R. M., Wold, C. N., 1997, Climate: is the past the key to the future?: Geologische Rundschau, 86, 471-491.
• Hay, W. W., DeConto, R. M., Wold, C. N., Wilson, K. M., Voigt, S., Schulz, M., Rossby-Wold, A., Dullo, W. -Chr., Ronov, A. B., and Balukhovsky, A., 1999, An alternative global Cretaceous paleogeography: in Barrera, E., and Johnson, C. (eds.), The Evolution of Cretaceous Ocean/Climate Systems, Geological Society of America Special Paper 332.
• Hay, W. W., Soeding, E., DeConto, R. M., and Wold, C. N. (2003) The Late Cenozoic uplift - climate change paradox: International Journal of Earth Sciences, v.91, p.746-774.
• Pollard, D. and DeConto, R. M. (in press) Antarctic sediment flux in the Oligocene simulated by a climate-ice sheet-sediment model: Palaeogeography, Palaeoclimatology, Palaeoecology.

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