HR: 12:05h
AN: A51H-08    [PDF]
TI: Sensitivity of inverted carbon sources and sinks from seasonally and interannual varying fossil fuel emission estimates
AU: * Gurney, K R
EM: keving@atmos.colostate.edu
AF: Kevin Robert Gurney, Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80521 United States
AU: Chen, Y
EM: didi@mit.edu
AF: Yu-Han Chen, Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, MA 02141 United States
AB: The possibility of a ?fossil fuel rectifier? is tested using two models (PCTM and MATCH:NCEP) that span the spectrum of vertical trapping and rectification as established in the TransCom 3 Atmospheric Carbon Inversion Intercomparison Experiment. Tests with a pseudo fossil fuel emissions field with varying seasonal amplitude suggests that a fossil fuel rectifier is likely to be a small factor in annual mean inversions. However, seasonality in the fossil signal and/or interannual variations in the spatial distribution has a significant impact on seasonal and interannual inversions. Though the level of seasonality in this emissions field is not well known, a 30% amplitude modification case in this exercise closely matches a recently suggested fossil amplitude derived from observational data. Inverse results including this level of fossil seasonality result in posterior flux estimates differing by up to 50% in the northern temperate land regions where the majority of the hypothesized northern land sink is located. This will vary with the extent to which simulated transport vertically traps surface fluxes as evidenced by the results from the two models chosen for this sensitivity study. The impact of interannual variations in the surface pattern of fossil fuel emissions have also be explored. In this experiment, inverse results which attempt to include regional shifts in fossil fuel over the last twenty years will be compared to a case in which the surface emission patterns are fixed. Exclusion of seasonal and interannual fossil fuel variations in inversion studies may lead to misinterpretation of results. This holds particular importance given that the proposed northern land sink and large fossil fuel emissions are coincident in space. Better representation of these variations is essential to maintain accuracy in inverse results as atmospheric inversion studies move to greater spatial and temporal resolution.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0322 Constituent sources and sinks
DE: 1610 Atmosphere (0315, 0325)
DE: 1615 Biogeochemical processes (4805)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting