HR: 1330h
AN: A52C-0818    [PDF]
TI: On the Relation Between Atmospheric Carbonyl Sulfide and Carbon Dioxide
AU: * Montzka, S A
EM: Stephen.A.Montzka@noaa.gov
AF: CMDL-NOAA, 325 Broadway ms:R/CMDL1, Boulder, CO 80305 United States
AU: Hall, B
EM: Bradley.Hall@noaa.gov
AF: CMDL-NOAA, 325 Broadway ms:R/CMDL1, Boulder, CO 80305 United States
AU: Mondeel, D J
EM: Debra.J.Mondeel@noaa.gov
AF: CIRES, University of Colorado, Boulder, CO 80309 United States
AU: Butler, J H
EM: James.H.Butler@noaa.gov
AF: CMDL-NOAA, 325 Broadway ms:R/CMDL1, Boulder, CO 80305 United States
AU: Dutton, G
EM: Geoff.Dutton@noaa.gov
AF: CIRES, University of Colorado, Boulder, CO 80309 United States
AU: Elkins, J W
EM: James.W.Elkins@noaa.gov
AF: CMDL-NOAA, 325 Broadway ms:R/CMDL1, Boulder, CO 80305 United States
AB: Measurements of carbonyl sulfide (COS) at ground-based sampling stations show large seasonal variations that are strongly related to those observed for carbon dioxide. Specifically, the relative magnitude of seasonal decreases observed for COS during spring and early summer at seven Northern Hemispheric (NH) sites are strongly correlated (r$^{2}$=0.97) to those observed for CO$_{2}$. The seven sites at which COS measurements were made since 2000 include coastal sites in the arctic (Barrow, 71N, and Alert, 82N), mid-latitudes (Trinidad Head, 41N), and on Hawaii (Kumukahi, 20N), continental U.S. sites (Wisconsin, 46N, and Harvard Forest, 43N), and high altitude sites (Mauna Loa, 20N, and Niwot Ridge 40N). This correlation most likely arises because a major loss process for both CO$_{2}$ and COS is reaction with carbonic anhydrase in photosynthesizing plants. But whereas CO$_{2}$ is respired by vegetation and other organisms, COS is not similarly produced. This important point may help explain why the spring-summer relative drawn-down observed for COS is about eight times larger than that for CO$_{2}$ at these NH sites. Given our understanding of interactions between trace gases and vegetation, the observations suggest that COS measurements could provide constraints on our understanding of CO$_{2}$ uptake by plants independent of the influence of respiration. Sources and non-vegetative sinks of COS are also considered; constraints to their influence on COS seasonality in the Northern Hemisphere may possibly be derived, for example, from measurements at Southern Hemispheric sites.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting