Updated ozone absorption cross section will reduce air quality compliance
Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone mea...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-12-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/15/13627/2015/acp-15-13627-2015.pdf |
| _version_ | 1818999196417523712 |
|---|---|
| author | E. D. Sofen M. J. Evans A. C. Lewis |
| author_facet | E. D. Sofen M. J. Evans A. C. Lewis |
| author_sort | E. D. Sofen |
| collection | DOAJ |
| description | Photometric ozone measurements rely upon an accurate value of the
ozone absorption cross section at 253.65 nm. This has recently
been re-evaluated by Viallon
et al. (2015) as 1.8 % smaller than the
accepted value (Hearn, 1961) used for the preceding 50
years. Thus, ozone measurements that applied the older cross section
systematically underestimate the amount of ozone in air. We correct
the reported historical surface data from North America and Europe and
find that this modest change in cross section has a significant impact
on the number of locations that are out of compliance with air quality
regulations if the air quality standards remain the same. We find 18,
23, and 20 % increases in the number of sites that are out of
compliance with current US, Canadian, and European ozone air quality
health standards for the year 2012. Should the new cross-section
value be applied, it would impact attainment of air quality standards
and compliance with relevant clean air acts, unless the air quality
target values themselves were also changed proportionately. We draw
attention to how a small change in gas metrology has a global impact
on attainment and compliance with legal air quality standards. We
suggest that further laboratory work to evaluate the new cross section
is needed and suggest three possible technical and policy responses
should the new cross section be adopted. |
| first_indexed | 2024-12-20T22:13:35Z |
| format | Article |
| id | doaj.art-ac9a8068d1b5493188630cf5a1843238 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-20T22:13:35Z |
| publishDate | 2015-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-ac9a8068d1b5493188630cf5a18432382022-12-21T19:25:07ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242015-12-011523136271363210.5194/acp-15-13627-2015Updated ozone absorption cross section will reduce air quality complianceE. D. Sofen0M. J. Evans1A. C. Lewis2Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, UKWolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, UKWolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, UKPhotometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.http://www.atmos-chem-phys.net/15/13627/2015/acp-15-13627-2015.pdf |
| spellingShingle | E. D. Sofen M. J. Evans A. C. Lewis Updated ozone absorption cross section will reduce air quality compliance Atmospheric Chemistry and Physics |
| title | Updated ozone absorption cross section will reduce air quality compliance |
| title_full | Updated ozone absorption cross section will reduce air quality compliance |
| title_fullStr | Updated ozone absorption cross section will reduce air quality compliance |
| title_full_unstemmed | Updated ozone absorption cross section will reduce air quality compliance |
| title_short | Updated ozone absorption cross section will reduce air quality compliance |
| title_sort | updated ozone absorption cross section will reduce air quality compliance |
| url | http://www.atmos-chem-phys.net/15/13627/2015/acp-15-13627-2015.pdf |
| work_keys_str_mv | AT edsofen updatedozoneabsorptioncrosssectionwillreduceairqualitycompliance AT mjevans updatedozoneabsorptioncrosssectionwillreduceairqualitycompliance AT aclewis updatedozoneabsorptioncrosssectionwillreduceairqualitycompliance |