HR: 1340h
AN: A13A-0082    [Abstracts]
TI: Design of an Atmospheric Observing Strategy for California's Carbon Cycle
AU: Tonse, S R
EM: stonse@lbl.gov
AF: E.O. Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 United States
AU: * Fischer, M L
EM: mlfischer@lbl.gov
AF: E.O. Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 United States
AU: Riley, W J
EM: wjriley@lbl.gov
AF: E.O. Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 United States
AB: We report the design of an atmospheric observing strategy to enable inverse estimation and attribution of CO2 (and other green house gases) exchange between the land surface and the atmosphere in California. Using models of the natural carbon cycle, fossil fuel emissions, and regional meteorology, we predict CO2 concentration "signals" that would be measured with current and proposed observing platforms. The CO2 sources can be broadly categorized as (1) strong and fairly constant positive fluxes from metropolitan areas (e.g., Los Angeles and San Francisco), (2) weaker but widely distributed positive and negative fluxes from diurnally and seasonally varying ecosystem exchange, and (3) weak but broadly distributed fossil emissions from the Central Valley. Maps of predicted CO2 signals for tower-based stations largely mirror the flux maps over land, while aircraft and column integrated signals (as would be observed with sounding instruments) reflect time-averaged fluxes from much larger areas. Predicted concentration signals away from urban areas are dependent on season, due primarily to variations in the natural carbon cycle, and secondarily to variations in fossil emissions and meteorology. Of significance for determining inflow boundary conditions, large plumes of CO2 enriched and depleted air (1-5 ppm) are predicted to advect from the Northwest to positions more than 300 km west of the California coast. This suggests that data from ocean-based stations must be incorporated into inversions using explicit estimations of regional terrestrial influence. We will also discuss ongoing work to: 1) identify a set of candidate observation stations for California, 2) estimate the influence of specific land surface elements to the measured signals, 3) predict atmospheric signals obtained from proposed strategies to increase ecosystem carbon sequestration.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0315 Biosphere/atmosphere interactions
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting