HR: 17:15h
AN: B54B-06    [Abstracts]
TI: Inter-annual Variability in Large-Scale Flooding of Aquatic Ecosystems and Associated CO2 Evasion in Amazonia: A Modeling Strategy
AU: * Howard, E A
EM: eahoward@wisc.edu
AF: Center for Sustainability and the Global Environment, University of Wisconsin - Madison 1710 University Ave., Madison, WI 53726 United States
AU: Coe, M T
EM: mtcoe@whrc.org
AF: Woods Hole Research Center, PO Box 296, Woods Hole, MA 02543 United States
AU: Foley, J A
EM: jfoley@wisc.edu
AF: Center for Sustainability and the Global Environment, University of Wisconsin - Madison 1710 University Ave., Madison, WI 53726 United States
AU: Costa, M H
EM: mhcosta@ufv.br
AF: Department of Agricultural Engineering, Federal University of Viçosa Av. P.H. Rolfs, s/n, Viçosa, MG 36570-000 Brazil
AB: The inter-annual variability of flooding in the Amazon basin is a major determinant of the spatial and temporal distribution of regional aquatic ecosystems and their associated CO₂ fluxes and ecosystem services. To date, excellent static remote sensing images showing the distribution of aquatic ecosystems at high and low water in 1995-6 have been produced that differentiate among ecologically and biogeochemically distinct categories for the basin (e.g., permanent open water, seasonally and permanently flooded vegetation) (Hess et al. 2003). However such a resource does not exist for a multi-year time series. To produce this key information, we apply a physically based modeling system to simulate hydrological fluxes and aquatic CO₂ emissions throughout the basin as a function of vegetation cover and time-transient climate. This modeling system includes an ecosystem land surface model (IBIS), a Terrestrial Hydrology Model with Biogeochemistry with dynamic floodplain (THMB, formerly HYDRA), and an aquatic C processing module that we are incorporating into THMB (Howard et al. in prep). THMB represents river discharge and flood extent and height throughout the Amazon Basin (Costa et al. 2002, Coe et al. in prep). It has been calibrated and validated with observations of river discharge, water height, and flooded area at numerous locations in the mainstem and headwaters. In order to simulate how the area of particular aquatic ecosystems changes over time, we fused the sub-grid scale classification of ecosystem distribution from Hess et al's single-year, classified remote sensing data (2003) with our simulation of seasonal and inter-annual hydrological variability. We will also discuss our efforts to use these multi-year simulation results, along with current observations of C fluxes from different ecosystems, to extrapolate and bound overall estimates of net CO₂ efflux from the Amazon River system.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0458 Limnology (1845, 4239, 4942)
DE: 1820 Floodplain dynamics
DE: 1836 Hydrological cycles and budgets (1218, 1655)
SC: Biogeosciences [B]
MN: Fall Meeting 2005