HR: 1340h
AN: A23C-1485    [Abstracts]
TI: Estimation of Flux Biases by Coupled MLEF-PCTM Model Using CO₂ Observations
AU: * Lokupitiya, R
EM: ravi@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, United States
AU: Zupanski, D
EM: zupanski@cira.colostate.edu
AF: Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO 80523, United States
AU: Denning, S
EM: denning@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, United States
AU: Parazoo, N
EM: nparazoo@atmos.colostate.edu
AF: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, United States
AU: Kawa, R
EM: kawa@maia.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, 8800 Greenbelt Road, Baltimore, MD 20771, United States
AU: Hanan, N
EM: niall@nrel.colostate.edu
AF: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, United States
AU: Zupanski, M
EM: zupanskim@cira.colostate.edu
AF: Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO 80523, United States
AB: We used an ensemble based data assimilation system, Maximum Likelihood Ensemble Filter (MLEF), which has been coupled with Parameterized Chemistry Transport Model (PCTM), to assimilate CO₂ observations. A pseudo data experiment showed that the coupled system is capable of recovering fluxes adequately in well- observed northern hemispheric regions. We assimilated 2 years of CO₂ observations from 49 flask sites and 15 continuous sites to estimate separate multiplicative biases in photosynthesis, respiration, and air-sea gas exchange. Spatial covariance in the biases was updated in the assimilation process. Flux bias estimates will be presented along with their uncertainties. It is assumed that the biases have 8-week time span and they are constant throughout that time period. Results show good constraint on model biases over North America and Europe. Some other regions (e.g. the South Atlantic, tropical contents) are unconstrained.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 3315 Data assimilation
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting