HR: 0800h
AN: A51C-0780    [Abstracts]
TI: The NOAA Nitrous Oxide Calibration Scale
AU: * Hall, B
EM: Bradley.Hall@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Crotwell, A
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 United States
AU: Dlugokencky, E
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Dutton, G
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 United States
AU: Butler, J
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, Boulder, CO 80305 United States
AU: Elkins, J
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, Boulder, CO 80305 United States
AB: The nitrous oxide (N2O) calibration scale developed by the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) was recently adopted by the WMO Global Atmosphere Watch (GAW) Program as the GAW N2O reference scale. NOAA/CMDL, along with the WMO GAW World Calibration Center (Garmisch-Partenkirchen, Germany), will likely be responsible for calibrating secondary compressed gas standards for a number of laboratories around the world. For N2O measurements made by different laboratories to be useful in examining global sources and sinks of N2O, inter-laboratory comparability must be within 0.2 ppb. To meet this stringent requirement for reproducibility, we configured an electron-capture gas chromatograph specifically for analysis of N2O comprssed gas standards. The NOAA calibration scale is maintained on this instrument through bi-monthly analysis of 5 secondary standards consisting of blends of natural and ultra-pure air (260-350 ppb N2O). Results from comparisons of these and other secondary standards on three N2O GCs operating in our laboratory suggest that the reproducibility of NOAA N2O calibrations can be maintained at or below 0.2 ppb. It is expected that this can be improved to 0.1 ppb through modest improvements in precision.
DE: 1694 Instruments and techniques
DE: 1610 Atmosphere (0315, 0325)
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0322 Constituent sources and sinks
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting