HR: 11:20h
AN: B41E-05    [PDF]
TI: Isotope discrimination and partitioning exercises at the scale of the atmospheric boundary layer
AU: * Berry, J
EM: joeberry@catalase.stanford.edu
AF: carnegie institution of washington, dept of global ecology, 260 panama st., stanford, ca 94305 United States
AU: helliker, b
EM: helliker@catalase.stanford.edu
AF: carnegie institution of washington, dept of global ecology, 260 panama st., stanford, ca 94305 United States
AU: bakwin, P
EM: Peter.Bakwin@noaa.gov
AF: National Oceanic and Atmospheric Administration- Climate Monitoring and Diagnostics Lab, 325 Broadway R/CMDL1, boulder, co 80305 United States
AU: davis, k
EM: davis@essc.psu.edu
AF: Department of Meteorology, Pennsylvania State University, 512 Walker Building, University Park, pa 16802 United States
AU: torn, m
EM: mstorn@lbl.gov
AF: Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Road Mailstop 90-1106, Berkeley, ca 94720 United States
AB: During the daytime the atmospheric boundary layer (ABL) is typically well mixed by convection up to about 1.5 km and moves across the land about 500 km per day. Underlying ecosystems modify carbon dioxide in the ABL through photosynthesis and respiration, and ABL air is ultimately replaced by air from the overlying free troposphere. Hence, measurements of carbon dioxide and isotopes in the ABL and the free troposphere offer the potential for regionally integrated estimates of isotope discrimination. We use tall-tower and airplane measurements of carbon dioxide and carbon and oxygen isotopes to develop estimates of ABL-scale isotope discrimination. We then utilize ecosystem-level measurements of the isotope ratio of respiration and land surface model estimates of photosynthetic discrimination to deconvolve net carbon dioxide fluxes into the gross components of photosynthesis and respiration at the regional scale.
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 0400 Biogeosciences
DE: 1615 Biogeochemical processes (4805)
DE: 3307 Boundary layer processes
SC: Biogeosciences [B]
MN: 2003 Fall Meeting