 |
| Titel |
Mass tracking for chemical analysis: the causes of ozone formation in southern Ontario during BAQS-Met 2007 |
| VerfasserIn |
P. A. Makar, J. Zhang, W. Gong, C. Stroud, D. Sills, K. L. Hayden, J. Brook, I. Levy, C. Mihele, M. D. Moran, D. W. Tarasick, H. He, D. Plummer |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 22 ; Nr. 10, no. 22 (2010-11-26), S.11151-11173 |
| Datensatznummer |
250008914
|
| Publikation (Nr.) |
 copernicus.org/acp-10-11151-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| A three-level nested regional air pollution model has been used to study the
processes leading to high ozone concentrations in the southern Great Lakes
region of North America. The highest resolution simulations show that
complex interactions between the lake-breeze circulation and the synoptic
flow lead to significant enhancements in the photochemical production and
transport of ozone at the local scale. Mass tracking of individual model
processes show that Lakes Erie and St. Clair frequently act as photochemical
ozone production regions, with average mid-day production rates of up to
3 ppbv per hour. Enhanced ozone levels are evident over these two lakes in
23-day-average surface ozone fields. Analysis of other model fields and
aircraft measurements suggests that vertical circulation enhances ozone
levels at altitudes up to 1500 m over Lake St. Clair, whereas subsidence
enhances ozone over Lake Erie in a shallow layer only 250 m deep. Mass
tracking of model transport shows that lake-breeze surface convergence zones
combined with the synoptic flow can then carry ozone and its precursors
hundreds of kilometers from these source areas, in narrow, elongated
features. Comparison with surface mesonet ozone observations confirm the
presence, magnitude, and timing of these features, which can create local
ozone enhancements on the order of 30 ppbv above the regional ozone levels.
Sensitivity analyses of model-predicted ozone and HOx concentrations
show that most of the region is VOC-limited, and that the secondary
oxidation pathways of aromatic hydrocarbons have a key role in setting the
region's ozone and HOx levels. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|