HR: 09:15h
AN: A31D-05    [Abstracts]
TI: Ozone-Depleting Gases in the Atmosphere: Results From 28 Years of Measurements by the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL)
AU: * Hurst, D F
EM: dale.hurst@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Campus Box 216, Boulder, CO 80309 United States
AU: * Hurst, D F
EM: dale.hurst@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Elkins, J W
EM: james.w.elkins@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Montzka, S A
EM: stephen.a.montzka@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Butler, J H
EM: james.h.butler@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Dutton, G S
EM: geoff.dutton@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Campus Box 216, Boulder, CO 80309 United States
AU: Dutton, G S
EM: geoff.dutton@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Hall, B D
EM: bradley.hall@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Mondeel, D J
EM: debra.j.mondeel@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Campus Box 216, Boulder, CO 80309 United States
AU: Mondeel, D J
EM: debra.j.mondeel@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Moore, F L
EM: fred.moore@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Campus Box 216, Boulder, CO 80309 United States
AU: Moore, F L
EM: fred.moore@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Nance, J D
EM: david.nance@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Campus Box 216, Boulder, CO 80309 United States
AU: Nance, J D
EM: david.nance@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Romashkin, P A
EM: pavel.romashkin@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Campus Box 216, Boulder, CO 80309 United States
AU: Romashkin, P A
EM: pavel.romashkin@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AU: Thompson, T M
EM: thayne.m.thompson@noaa.gov
AF: NOAA Climate Monitoring and Diagnostics Laboratory, 325 Broadway, R/CMDL1, Boulder, CO 80305 United States
AB: Back in 1978, NOAA/CMDL initiated the weekly filling of flasks at CMDL observatories in Alaska, Hawaii, American Samoa, and Antarctica for analyses of CFC-11, CFC-12 and N₂O in the home laboratory. A decade later, each observatory was outfitted with an automated gas chromatograph to make routine, in situ measurements of these three source gases plus methyl chloroform and carbon tetrachloride. Both measurement programs are ongoing, having expanded over the years to include methyl halides and substitutes for regulated halocarbons, to presently account for 95% of the total burden of long-lived Cl and Br believed to enter the stratosphere. These long-term monitoring data have been assimilated into temporal records of the global tropospheric burdens of ozone-depleting chlorine and bromine which are critical input to models that predict future trends in stratospheric ozone. Other information pivotal to ozone projections, such as the atmospheric lifetimes of source gases, stratospheric entry values for total chlorine and total bromine, and identification of the stratospheric sink regions for long-lived source gases, has been gained from in situ measurements by NOAA/CMDL instruments aboard NASA high-altitude aircraft (ER-2 and WB-57) and balloons since 1991. Though CMDL's routine monitoring activities provide important historical records of halogenated source gases in the atmosphere, significant inaccuracies in ozone projections may propagate from the uncertain estimates of impending emissions of ozone-depleting gases. Scenarios of future halocarbon emissions require substantial assumptions about past and pending compliance with the Montreal Protocol, and the sizes and release rates of existing global reservoirs (banks) of halocarbons. Recent work by CMDL has focused on quantifying halocarbon bank emission rates in Russia, the USA, and Canada through geographically extensive measurements aboard trains and low-altitude aircraft. The USA and Canada results indicate that globally significant emissions continued to emanate from these two countries in 2003, more than 7 years after the Montreal Protocol-mandated production phase-out. Large-scale, measurement-based emission estimates such as these provide important checks of our understanding of contemporary halocarbon emissions and will undoubtedly help to improve the accuracy of projected future halocarbon abundances and ozone recovery rates.
DE: 0322 Constituent sources and sinks
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005