Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate
A parameterization was developed for the heterogeneous reaction probability (<i>γ</i>) of N<sub>2</sub>O<sub>5</sub> as a function of temperature, relative humidity (RH), particle composition, and phase state, for use in advanced air quality models. The reaction p...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2008-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/8/5295/2008/acp-8-5295-2008.pdf |
| _version_ | 1818213543090061312 |
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| author | P. V. Bhave K. M. Foley J. M. Davis |
| author_facet | P. V. Bhave K. M. Foley J. M. Davis |
| author_sort | P. V. Bhave |
| collection | DOAJ |
| description | A parameterization was developed for the heterogeneous reaction probability (<i>γ</i>) of N<sub>2</sub>O<sub>5</sub> as a function of temperature, relative humidity (RH), particle composition, and phase state, for use in advanced air quality models. The reaction probabilities on aqueous NH<sub>4</sub>HSO<sub>4</sub>, (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>, and NH<sub>4</sub>NO<sub>3</sub> were modeled statistically using data and uncertainty values compiled from seven different laboratory studies. A separate regression model was fit to laboratory data for dry NH<sub>4</sub>HSO<sub>4</sub> and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> particles, yielding lower <i>γ</i> values than the corresponding aqueous parameterizations. The regression equations reproduced 80% of the laboratory data within a factor of two and 63% within a factor of 1.5. A fixed value was selected for <i>γ</i> on ice-containing particles based on a review of the literature. The combined parameterization was applied under atmospheric conditions representative of the eastern United States using 3-dimensional fields of temperature, RH, sulfate, nitrate, and ammonium. The resulting spatial distributions of <i>γ</i> were contrasted with three other parameterizations that have been applied in air quality models in the past and with atmospheric observational determinations of <i>γ</i>. Our equations lay the foundation for future research that will parameterize the suppression of <i>γ</i> when inorganic ammoniated particles are mixed or coated with organic material. Our analyses draw attention to a major uncertainty in the available laboratory data at high RH and highlight a critical need for future laboratory measurements of <i>γ</i> at low temperature and high RH to improve model simulations of N<sub>2</sub>O<sub>5</sub> hydrolysis during wintertime conditions. |
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| id | doaj.art-9fbd5bbbb7e843bc8163b41e75e4eb75 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-12T06:05:57Z |
| publishDate | 2008-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-9fbd5bbbb7e843bc8163b41e75e4eb752022-12-22T00:35:17ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242008-09-0181752955311Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrateP. V. BhaveK. M. FoleyJ. M. DavisA parameterization was developed for the heterogeneous reaction probability (<i>γ</i>) of N<sub>2</sub>O<sub>5</sub> as a function of temperature, relative humidity (RH), particle composition, and phase state, for use in advanced air quality models. The reaction probabilities on aqueous NH<sub>4</sub>HSO<sub>4</sub>, (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>, and NH<sub>4</sub>NO<sub>3</sub> were modeled statistically using data and uncertainty values compiled from seven different laboratory studies. A separate regression model was fit to laboratory data for dry NH<sub>4</sub>HSO<sub>4</sub> and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> particles, yielding lower <i>γ</i> values than the corresponding aqueous parameterizations. The regression equations reproduced 80% of the laboratory data within a factor of two and 63% within a factor of 1.5. A fixed value was selected for <i>γ</i> on ice-containing particles based on a review of the literature. The combined parameterization was applied under atmospheric conditions representative of the eastern United States using 3-dimensional fields of temperature, RH, sulfate, nitrate, and ammonium. The resulting spatial distributions of <i>γ</i> were contrasted with three other parameterizations that have been applied in air quality models in the past and with atmospheric observational determinations of <i>γ</i>. Our equations lay the foundation for future research that will parameterize the suppression of <i>γ</i> when inorganic ammoniated particles are mixed or coated with organic material. Our analyses draw attention to a major uncertainty in the available laboratory data at high RH and highlight a critical need for future laboratory measurements of <i>γ</i> at low temperature and high RH to improve model simulations of N<sub>2</sub>O<sub>5</sub> hydrolysis during wintertime conditions.http://www.atmos-chem-phys.net/8/5295/2008/acp-8-5295-2008.pdf |
| spellingShingle | P. V. Bhave K. M. Foley J. M. Davis Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate Atmospheric Chemistry and Physics |
| title | Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate |
| title_full | Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate |
| title_fullStr | Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate |
| title_full_unstemmed | Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate |
| title_short | Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate |
| title_sort | parameterization of n sub 2 sub o sub 5 sub reaction probabilities on the surface of particles containing ammonium sulfate and nitrate |
| url | http://www.atmos-chem-phys.net/8/5295/2008/acp-8-5295-2008.pdf |
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