HR: 1340h
AN: A13D-1516    [Abstracts]
TI: Evaluating the Capacity of Global CO2 Flux and Atmospheric Transport Models to Incorporate New Satellite Observations
AU: * Kawa, S R
EM: stephan.r.kawa@nasa.gov
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Collatz, G J
EM: george.j.collatz@nasa.gov
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Erickson, D J
EM: ericksondj@ornl.gov
AF: DOE, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
AU: Denning, A S
EM: denning@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523, United States
AU: Wofsy, S C
EM: steven_wofsy@harvard.edu
AF: Harvard University, Department of Earth and Planetary Sciences, Cambridge, MA 02138, United States
AU: Andrews, A E
EM: arlyn.andrews@noaa.gov
AF: NOAA, Earth Science Research Laboratory, Boulder, CO 80305, United States
AB: As we enter the new era of satellite remote sensing for CO2 and other carbon cycle-related quantities, advanced modeling and analysis capabilities are required to fully capitalize on the new observations. Model estimates of CO2 surface flux and atmospheric transport are required for initial constraints on inverse analyses, to connect atmospheric observations to the location of surface sources and sinks, and ultimately for future projections of carbon-climate interactions. For application to current, planned, and future remotely sensed CO2 data, it is desirable that these models are accurate and unbiased at time scales from less than daily to multi-annual and at spatial scales from several kilometers or finer to global. Here we focus on simulated CO2 fluxes from terrestrial vegetation and atmospheric transport mutually constrained by analyzed meteorological fields from the Goddard Modeling and Assimilation Office for the period 1998 through 2006. Use of assimilated meteorological data enables direct model comparison to observations across a wide range of scales of variability. The biospheric fluxes are produced by the CASA model at 1x1 degrees on a monthly mean basis, modulated hourly with analyzed temperature and sunlight. Both physiological and biomass burning fluxes are derived using satellite observations of vegetation, burned area (as in GFED-2), and analyzed meteorology. For the purposes of comparison to CO2 data, fossil fuel and ocean fluxes are also included in the transport simulations. In this presentation we evaluate the model's ability to simulate CO2 flux and mixing ratio variability in comparison to in situ observations at sites in Northern mid latitudes and the continental tropics. The influence of key process representations is inferred. We find that the model can resolve much of the hourly to synoptic variability in the observations, although there are limits imposed by vertical resolution of boundary layer processes. The seasonal cycle and its interannual variations generally respond adequately, but discrepancies in the tropics suggest the need for a refinement of the soil moisture dependence of the respiration flux in CASA. Examples and inferences for interpretation of satellite data will be discussed. In general, the fidelity of these simulations leads us to anticipate incorporation of real-time, highly resolved remote sensing and other observations into quantitative analyses that will reduce uncertainty in the terrestrial CO2 sink and revolutionize our understanding of the key processes controlling atmospheric CO2 and its evolution with time.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere: composition and chemistry
DE: 0428 Carbon cycling (4806)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting