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| Titel |
The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis |
| VerfasserIn |
D. Helmig, L. Ganzeveld, T. Butler, S. J. Oltmans |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 7, no. 1 ; Nr. 7, no. 1 (2007-01-05), S.15-30 |
| Datensatznummer |
250004342
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| Publikation (Nr.) |
 copernicus.org/acp-7-15-2007.pdf |
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| Zusammenfassung |
| Recent research on snowpack processes and
atmosphere-snow gas exchange has demonstrated that chemical and physical
interactions between the snowpack and the overlaying atmosphere have a
substantial impact on the composition of the lower troposphere. These
observations also imply that ozone deposition to the snowpack possibly
depends on parameters including the quantity and composition of deposited
trace gases, solar irradiance, snow temperature and the substrate below the
snowpack. Current literature spans a remarkably wide range of ozone
deposition velocities (vdO3); several studies even reported positive
ozone fluxes out of the snow. Overall, published values range from ~–3<vdO3<2 cm s−1,
although most data are within 0<vdO3<0.2 cm s−1. This literature reveals a high uncertainty in
the parameterization and the magnitude of ozone fluxes into (and possibly
out of) snow-covered landscapes. In this study a chemistry and tracer
transport model was applied to evaluate the applicability of the published
vdO3 and to investigate the sensitivity of tropospheric ozone towards
ozone deposition over Northern Hemisphere snow-covered land and sea-ice.
Model calculations using increasing vdO3 of 0.0, 0.01, 0.05 and 0.10 cm s−1
resulted in general ozone sensitivities up to 20–30% in the
Arctic surface layer, and of up to 130% local increases in selected
Northern Latitude regions. The simulated ozone concentrations were compared
with mean January ozone observations from 18 Arctic stations. Best agreement
between the model and observations, not only in terms of absolute
concentrations but also in the hourly ozone variability, was found by
applying an ozone deposition velocity in the range of 0.00–0.01 cm s−1,
which is smaller than most literature data and also significantly lower
compared to the value of 0.05 cm s−1 that is commonly applied in
large-scale atmospheric chemistry models. This sensitivity analysis
demonstrates that large errors in the description of the wintertime
tropospheric ozone budget stem from the uncertain magnitude of ozone
deposition rates and the inability to properly parameterize ozone fluxes to
snow-covered landscapes. |
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