Multi-trophic communities experience cyclic changes in environmental conditions that influence the nature and strength of ecological interactions. Seasonal temperature variations create temporal refuges, which can favor coexistence of consumers sharing a common resource. How does temperature sensitivity interplay with other mechanisms in maintaining species coexistence? How will warming affect biodiversity?
Spatial patterns in the distribution of zooplankton arise from social interactions between individuals. In the Southern Ocean, krill often assemble in swarms and schools, the dynamics of which have important ecological consequences. Mathematical and numerical models are employed to study the interplay of biological and physical processes that contribute to the observed patchiness. (Dissertation title: "Dynamics of marine zooplankton: social behavior, ecological interactions, and physically-induced variability")
Nonlinear ecological systems may possess asymptotically stable equilibria, yet experience transient excursions away from equilibrium induced by small external perturbations. Reactivity is a measure of the potential to amplify such perturbations. How does reactivity depend on the parameters of the underlying model? What ecological mechanisms cause transient dynamics in food webs?
collaborator: Hal Caswell Presentation: ESA Symposium on transient dynamics (August 2008)
Air-sea fluxes of carbon dioxide and oxygen
Changes in ocean temperature affect the solubility of carbon dioxide and oxygen. In the Southern Ocean, ENSO and the Southern Annular Mode are thought to drive sea surface temperature variability. What is their impact on the air-sea exchange of soluble gases?
collaborators: Mick Follows, Stephanie Dutkiewicz, Arnaud Czaja, John Marshall
presentation: AGU fall meeting, San Francisco CA (December 2006)
Recent presentations
[view] ESA annual meeting (Symposium on transient dynamics), Milwaukee WI (August 2008) [view] Ocean Sciences meeting, Orlando FL (March 2008) [view] MIT Thesis Defense, Cambridge MA (October 2007) [view] WHOI Physical Oceanography Seminar, Woods Hole MA (September 2007) [view] ESA annual meeting, San Jose CA (August 2007) [view] AGU fall meeting, San Francisco CA (December 2006)
