Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model
The photolysis of HONO is important for the atmospheric HO<sub>x</sub> (OH + HO<sub>2</sub>) radical budget and ozone formation, especially in polluted air. Nevertheless, owing to the incomplete knowledge of HONO sources, realistic HONO mechani...
| Päätekijät: | , , , |
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| Aineistotyyppi: | Artikkeli |
| Kieli: | English |
| Julkaistu: |
Copernicus Publications
2012-10-01
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| Sarja: | Atmospheric Chemistry and Physics |
| Linkit: | http://www.atmos-chem-phys.net/12/9977/2012/acp-12-9977-2012.pdf |
| _version_ | 1829495466385997824 |
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| author | Y. F. Elshorbany B. Steil C. Brühl J. Lelieveld |
| author_facet | Y. F. Elshorbany B. Steil C. Brühl J. Lelieveld |
| author_sort | Y. F. Elshorbany |
| collection | DOAJ |
| description | The photolysis of HONO is important for the atmospheric HO<sub>x</sub> (OH + HO<sub>2</sub>) radical budget and ozone formation, especially in polluted air. Nevertheless, owing to the incomplete knowledge of HONO sources, realistic HONO mechanisms have not yet been implemented in global models. We investigated measurement data sets from 15 field measurement campaigns conducted in different countries worldwide. It appears that the HONO/NO<sub>x</sub> ratio is a good proxy predictor for HONO mixing ratios under different atmospheric conditions. From the robust relationship between HONO and NO<sub>x</sub>, a representative mean HONO/NO<sub>x</sub> ratio of 0.02 has been derived. Using a global chemistry-climate model and employing this HONO/NO<sub>x</sub> ratio, realistic HONO levels are simulated, being about one order of magnitude higher than the reference calculations that only consider the reaction OH + NO → HONO. The resulting enhancement of HONO significantly impacts HO<sub>x</sub> levels and photo-oxidation products (e.g, O<sub>3</sub>, PAN), mainly in polluted regions. Furthermore, the relative enhancements in OH and secondary products are higher in winter than in summer, thus enhancing the oxidation capacity in polluted regions, especially in winter when other photolytic OH sources are of minor importance. Our results underscore the need to improve the understanding of HONO chemistry and its representation in atmospheric models. |
| first_indexed | 2024-12-16T07:11:24Z |
| format | Article |
| id | doaj.art-9a0a4e5cd27f4b5ba73f94ed6d6b6dab |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-16T07:11:24Z |
| publishDate | 2012-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-9a0a4e5cd27f4b5ba73f94ed6d6b6dab2022-12-21T22:39:54ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242012-10-01122099771000010.5194/acp-12-9977-2012Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC modelY. F. ElshorbanyB. SteilC. BrühlJ. LelieveldThe photolysis of HONO is important for the atmospheric HO<sub>x</sub> (OH + HO<sub>2</sub>) radical budget and ozone formation, especially in polluted air. Nevertheless, owing to the incomplete knowledge of HONO sources, realistic HONO mechanisms have not yet been implemented in global models. We investigated measurement data sets from 15 field measurement campaigns conducted in different countries worldwide. It appears that the HONO/NO<sub>x</sub> ratio is a good proxy predictor for HONO mixing ratios under different atmospheric conditions. From the robust relationship between HONO and NO<sub>x</sub>, a representative mean HONO/NO<sub>x</sub> ratio of 0.02 has been derived. Using a global chemistry-climate model and employing this HONO/NO<sub>x</sub> ratio, realistic HONO levels are simulated, being about one order of magnitude higher than the reference calculations that only consider the reaction OH + NO → HONO. The resulting enhancement of HONO significantly impacts HO<sub>x</sub> levels and photo-oxidation products (e.g, O<sub>3</sub>, PAN), mainly in polluted regions. Furthermore, the relative enhancements in OH and secondary products are higher in winter than in summer, thus enhancing the oxidation capacity in polluted regions, especially in winter when other photolytic OH sources are of minor importance. Our results underscore the need to improve the understanding of HONO chemistry and its representation in atmospheric models.http://www.atmos-chem-phys.net/12/9977/2012/acp-12-9977-2012.pdf |
| spellingShingle | Y. F. Elshorbany B. Steil C. Brühl J. Lelieveld Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model Atmospheric Chemistry and Physics |
| title | Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model |
| title_full | Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model |
| title_fullStr | Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model |
| title_full_unstemmed | Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model |
| title_short | Impact of HONO on global atmospheric chemistry calculated with an empirical parameterization in the EMAC model |
| title_sort | impact of hono on global atmospheric chemistry calculated with an empirical parameterization in the emac model |
| url | http://www.atmos-chem-phys.net/12/9977/2012/acp-12-9977-2012.pdf |
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