An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8
A bidirectional air–surface exchange scheme for atmospheric ammonia was incorporated into the Stochastic Time-Inverted Lagrangian Transport air quality model (STILT-Chem v0.8). STILT-Chem v0.8 was then applied to simulate atmospheric ammonia concentrations at 53 measurement sites in the provi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-05-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/7/1037/2014/gmd-7-1037-2014.pdf |
| _version_ | 1811194315239587840 |
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| author | D. Wen L. Zhang J. C. Lin R. Vet M. D. Moran |
| author_facet | D. Wen L. Zhang J. C. Lin R. Vet M. D. Moran |
| author_sort | D. Wen |
| collection | DOAJ |
| description | A bidirectional air–surface exchange scheme for atmospheric ammonia
was incorporated into the Stochastic Time-Inverted Lagrangian
Transport air quality model (STILT-Chem v0.8). STILT-Chem v0.8 was
then applied to simulate atmospheric ammonia concentrations at 53
measurement sites in the province of Ontario, Canada for a six-month
period from 1 June to 30 November 2006. In addition to the
bidirectional scheme, two unidirectional dry deposition schemes
were tested. Comparisons of modeled ammonia concentrations against
observations show that all three schemes can reasonably predict
observations. For sites with low observed ammonia concentrations,
the bidirectional scheme clearly overestimated ammonia
concentrations during crop-growing season. Although all three schemes tended to underestimate
ammonia concentrations after mid-October and for sites with elevated observed
concentrations, mainly due to underestimated NH<sub>3</sub> emission inventory after
mid-October and/or underestimated emission potentials for those sites, the
bidirectional scheme performed better because of its introduction of
compensation points into the flux
calculation parameterization. In addition to uncertainties in the emission inventory, the results of additional sensitivity
tests suggest that uncertainties in the input values of emission
potentials in the bidirectional scheme greatly affect the accuracy
of modeled ammonia concentrations. The use of much larger emission
potentials in the bidirectional scheme and larger anthropogenic NH<sub>3</sub>
emission after mid-October than provided in the model emissions files is needed for accurate
prediction of elevated ammonia concentrations at intensive
agricultural locations. |
| first_indexed | 2024-04-12T00:23:49Z |
| format | Article |
| id | doaj.art-d6e8391b0123496c9311aeec869468f5 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-04-12T00:23:49Z |
| publishDate | 2014-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-d6e8391b0123496c9311aeec869468f52022-12-22T03:55:36ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032014-05-01731037105010.5194/gmd-7-1037-2014An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8D. Wen0L. Zhang1J. C. Lin2R. Vet3M. D. Moran4Waterloo Atmosphere-Land Interactions Research Group, Department of Earth and Environmental Sciences, University of Waterloo, CanadaAir Quality Research Division, Science and Technology Branch, Environment Canada, CanadaWaterloo Atmosphere-Land Interactions Research Group, Department of Earth and Environmental Sciences, University of Waterloo, CanadaAir Quality Research Division, Science and Technology Branch, Environment Canada, CanadaAir Quality Research Division, Science and Technology Branch, Environment Canada, CanadaA bidirectional air–surface exchange scheme for atmospheric ammonia was incorporated into the Stochastic Time-Inverted Lagrangian Transport air quality model (STILT-Chem v0.8). STILT-Chem v0.8 was then applied to simulate atmospheric ammonia concentrations at 53 measurement sites in the province of Ontario, Canada for a six-month period from 1 June to 30 November 2006. In addition to the bidirectional scheme, two unidirectional dry deposition schemes were tested. Comparisons of modeled ammonia concentrations against observations show that all three schemes can reasonably predict observations. For sites with low observed ammonia concentrations, the bidirectional scheme clearly overestimated ammonia concentrations during crop-growing season. Although all three schemes tended to underestimate ammonia concentrations after mid-October and for sites with elevated observed concentrations, mainly due to underestimated NH<sub>3</sub> emission inventory after mid-October and/or underestimated emission potentials for those sites, the bidirectional scheme performed better because of its introduction of compensation points into the flux calculation parameterization. In addition to uncertainties in the emission inventory, the results of additional sensitivity tests suggest that uncertainties in the input values of emission potentials in the bidirectional scheme greatly affect the accuracy of modeled ammonia concentrations. The use of much larger emission potentials in the bidirectional scheme and larger anthropogenic NH<sub>3</sub> emission after mid-October than provided in the model emissions files is needed for accurate prediction of elevated ammonia concentrations at intensive agricultural locations.http://www.geosci-model-dev.net/7/1037/2014/gmd-7-1037-2014.pdf |
| spellingShingle | D. Wen L. Zhang J. C. Lin R. Vet M. D. Moran An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8 Geoscientific Model Development |
| title | An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8 |
| title_full | An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8 |
| title_fullStr | An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8 |
| title_full_unstemmed | An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8 |
| title_short | An evaluation of ambient ammonia concentrations over southern Ontario simulated with different dry deposition schemes within STILT-Chem v0.8 |
| title_sort | evaluation of ambient ammonia concentrations over southern ontario simulated with different dry deposition schemes within stilt chem v0 8 |
| url | http://www.geosci-model-dev.net/7/1037/2014/gmd-7-1037-2014.pdf |
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