HR: 13:55h
AN: B42B-02    [PDF]
TI: Regional CO$_2$ Fluxes Using a Network of Carbon Dioxide Mixing Ratio Sensors
AU: * Richardson, S J
EM: srichardson@psu.edu
AF: Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802 United States
AU: Miles, N L
EM: nmiles@essc.psu.edu
AF: Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802 United States
AU: Davis, K J
EM: davis@essc.psu.edu
AF: Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802 United States
AU: Wang, W
EM: wang@essc.psu.edu
AF: Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802 United States
AU: Denning, A S
EM: denning@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, 200 West Lake Street, Fort Collins, CO 80523 United States
AU: Bakwin, P S
EM: pbakwin@cmdl.noaa.gov
AF: NOAA, Climate Monitoring and Diagnostics Laboratory, 325 Broadway R/CMDL, Boulder, CO 80305 United States
AU: Berry, J
EM: joeberry@GlobalEcology.stanford.edu
AF: Department of Global Ecology, Carnegie Institute of Washington, 260 Panama Street, Stanford, CA 94305 United States
AU: Helliker, B
EM: helliker@catalase.stanford.edu
AF: Department of Global Ecology, Carnegie Institute of Washington, 260 Panama Street, Stanford, CA 94305 United States
AB: Inverse studies of CO$_2$ mixing ratio are traditionally conducted at coarse spatial and temporal resolution. This limits our ability to evaluate efforts to upscale chamber and stand level CO$_2$ flux measurements to regional scales, where coherent climate and ecosystem mechanisms govern the carbon cycle. We present an effort to implement atmospheric budget or inversion methodology on a regional scale. A first step towards this end is the evaluation of a network of six relatively inexpensive CO$_2$ mixing ratio measurement systems deployed on towers in northern Wisconsin as part of the Chequamegon Ecosystem-Atmosphere Study. Five systems are distributed on a circle of roughly 150-km radius, while one system is centrally located. All measurements are taken at a height of 76 m. The systems use LiCor-820 infrared CO$_2$ analyzers and are calibrated every two hours using four samples known to within $\pm$ 0.05 ppm CO$_2$. Field tests prior to deployment in which the six systems sampled the same air indicate agreement of the systems to within 0.5--1.0 ppm from the mean during relatively quiescent periods. Tests using tanks containing known CO$_2$ concentrations exhibit standard deviations of 1.0 ppm or less. If network precision and accuracy prove to be sufficiently high, these data will detect horizontal gradients in CO$_2$ mixing ratios caused by net ecosystem-atmosphere exchange. These horizontal gradients will be the basis for using atmospheric budget methods to derive regional fluxes with spatial and temporal resolution fine enough to warrant comparison to the ChEAS regional flux tower network. Results from the deployment (July--October 2003) are presented.
DE: 1694 Instruments and techniques
DE: 3322 Land/atmosphere interactions
SC: Biogeosciences [B]
MN: 2003 Fall Meeting