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lauderdale

New Postdoc Jonathan Lauderdale

Jonathan Lauderdale is a physical oceanographer and ocean biogeochemical modeller “intrigued” by the mechanisms through which the ocean can alter Earth’s climate and atmospheric CO2 concentration both in the past and under future anthropogenic changes. So far his focus has been on high latitude regions, particularly the Southern Ocean. He mostly uses global coarse resolution numerical models of ocean circulation coupled to simplified biogeochemistry routines, but also exploits composite tracers to reveal how different components of carbon and nutrient cycles operate.

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Publication

Clayton, S., S. Dutkiewicz , O. Jahn, and M.J. Follows (2013), Ocean eddies and dispersal maintain phytoplankton diversity, Limnology and Oceanography, Fluids and Environments, Volume 3: 182–197, doi: 10.1215/21573689-2373515

Publication

Ward, B.A., S. Dutkiewicz, and M.J. Follows (2013), Top-down and bottom-up controls in a global size-structured plankton food-web model, Journal of Plankton Research , 0, 1-17, doi: 10.1093/plankt/fbt097

Publication

Lauderdale, J.M., A.C.N. Garabato, K.I.C. Oliver, M.J. Follows and R.G. Williams(2013), Wind-driven changes in Southern Ocean residual circulation, ocean carbon reservoirs and atmospheric CO2, Climate Dynamics, vol. 41, pp. 2145, doi: 10.1007%2Fs00382-012-1650-3

Diatoms_through_the_microscope

The dynamics of dining in an all-you-can-eat-phytoplankton buffet

Predators’ switching towards the most abundant prey is a mechanism that stabilizes population dynamics and helps overcome competitive exclusion of species in food webs. However, current formulations of active prey-switching in marine ecosystem models display non-maximal feeding; the total ingestion of prey by predators decays exponentially with the number of prey species even though the total prey biomass stays constant.

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Publication:

Vallina, S. M. , B. A. Ward, S. Dutkiewicz, and M. J. Follows (2013), Maximal feeding with active prey-switching: a kill-the-winner functional response and its effect on global diversity and biogeography, Progress in Oceanography, 120, 93–109, doi: 10.1016/j.pocean.2013.08.001

Publication

Goebel, N.L., C.A. Edwards, J.P. Zehr, M.J. Follows and S.G. Morgan (2013), Modeled phytoplankton diversity and productivity in the California Current SystemEcological Modelling, vol. 264, pp. 37, doi: 10.1016/j.ecolmodel.2012.11.008

800px-Phytoplankton_-_the_foundation_of_the_oceanic_food_chain

Winners and losers in a warming ocean

by Alli Gold Roberts (MIT Joint Program on the Science and Policy of Global Change)
Read this story at MIT News

Phytoplankton — small plant-like organisms that serve as the base of the marine ecosystem — play a crucial role in maintaining the health of our oceans by consuming carbon dioxide and fueling the food web. But with a changing climate, which of these vital organisms will survive, and what impact will their demise have on fish higher up the chain?
Stephanie Dutkiewicz, a researcher with the MIT Joint Program on the Science and Policy of Global Change, and her colleagues developed a model that investigates the potential effects of climate change on phytoplankton.

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On the potential role of marine calcifiers in glacial-interglacial dynamics

Ice-core measurements reveal a highly asymmetric cycle in Antarctic temperature and atmospheric CO2 over the last 800,000 years. Both CO2 and temperature decrease over 100,000 years going into a glacial period, then rise steeply over less than 10,000 years at the end of a glacial. There does not yet exist wide agreement about the causes of this cycle or about the origin of its shape. In this article, recently accepted in the journal Global Biogeochemical Cycles, Darwin researchers Anne Willem Omta, Mick Follows and co-authors, explore the possibility that an ecologically driven oscillator may play a role in the dynamics.

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Publication

Ward, B.A., M. Schartau, A. Oschlies, A.P. Martin, M.J. Follows and T.R. Anderson, TR (2013), When is a biogeochemical model too complex? Objective model reduction and selection for North Atlantic time-series sites Progress in Oceanography, vol. 116, pp. 49, doi:10.1016/j.pocean.2013.06.002