SS1.05 How Will Aquatic Ecosystems Respond to Climate Change?
Date: Tuesday, June 11, 2002
Time: 3:00:00 PM
Location: Oak Bay
 
PahlowM, Dalhousie University, Halifax, Canada, pahlowm@mar.dfo-mpo.gc.ca
Vézina, A, F, Bedford Institute of Oceanography, Dartmouth, Canada, vezinaa@dfo-mpo.gc.ca
Wright, D, G, Bedford Institute of Oceanography, Dartmouth, Canada, WRIGHTDAN@mar.dfo-mpo.gc.ca
 
A BACTERIA-DOM MODEL FOR LONG-TERM CLIMATE STUDIES
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We have developed a simple plankton model with a formulation of bacterial DOM utilization which focuses on substrate-level acclimation, respiration, and interaction with inorganic nutrients. In combination with abiotic (photochemical) DOM transformations, we obtain a more general representation of Bacteria-DOM dynamics than models based on saturation kinetics. Sensitivity analyses reveal a significant influence of temperature on bacteria-DOM dynamics and the balance of DOM fractions remineralized to CO2 and exported to the deep ocean. In order to examine the potential impact of the relationship between temperature and bacteria-DOM interactions on the development of the global carbon cycle over long time scales, we couple our plankton-DOM model with a zonally averaged model of the thermohaline circulation for paleoclimate studies (D. G. Wright and Stokker, T. F., 1991. J. Phys. Oceanogr. 21: 1713-1724). We investigate the roles of bacteria and DOM for climatic feedbacks between temperature and CO2 during glacial-interglacial transitions.