The regional atmospheric chemistry mechanism, version 2

Goliff, W. S.; Stockwell, William R.; Lawson, Charlene V.

doi:10.1016/j.atmosenv.2012.11.038

Cited by 230 publications

(161 citation statements)

References 47 publications

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“…We used the lumped Regional Atmospheric Chemistry Mechanism version 2 (RACM2) (Stockwell et al, 1997;Goliff et al, 2013) and the near-explicit Master Chemical Mechanism version 3.3.1 (MCMv331) (Jenkin et al, , 2015Bloss et al, 2005). An exhaustive list of model constraints is displayed in Table 1.…”

Section: Model Descriptionmentioning

confidence: 99%

Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range

et al. 2017

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Abstract. Chemical models must correctly calculate the ozone formation rate, P(O 3 ), to accurately predict ozone levels and to test mitigation strategies. However, air quality models can have large uncertainties in P(O 3 ) calculations, which can create uncertainties in ozone forecasts, especially during the summertime when P(O 3 ) is high. One way to test mechanisms is to compare modeled P(O 3 ) to direct measurements. During summer 2014, the Measurement of Ozone Production Sensor (MOPS) directly measured net P(O 3 ) in Golden, CO, approximately 25 km west of Denver along the Colorado Front Range. Net P(O 3 ) was compared to rates calculated by a photochemical box model that was constrained by measurements of other chemical species and that used a lumped chemical mechanism and a more explicit one. Median observed P(O 3 ) was up to a factor of 2 higher than that modeled during early morning hours when nitric oxide (NO) levels were high and was similar to modeled P(O 3 ) for the rest of the day. While all interferences and offsets in this new method are not fully understood, simulations of these possible uncertainties cannot explain the observed P(O 3 ) behavior. Modeled and measured P(O 3 ) and peroxy radical (HO 2 and RO 2 ) discrepancies observed here are similar to those presented in prior studies. While a missing atmospheric organic peroxy radical source from volatile organic compounds coemitted with NO could be one plausible solution to the P(O 3 ) discrepancy, such a source has not been identified and does not fully explain the peroxy radical model-data mismatch. If the MOPS accurately depicts atmospheric P(O 3 ), then these results would imply that P(O 3 ) in Golden, CO, would be NO x -sensitive for more of the day than what is calculated by models, extending the NO x -sensitive P(O 3 ) regime from the afternoon further into the morning. These results couldPublished by Copernicus Publications on behalf of the European Geosciences Union. 11274 B. C. Baier et al.: Higher measured than modeled ozone production affect ozone reduction strategies for the region surrounding Golden and possibly other areas that do not comply with national ozone regulations. Thus, it is important to continue the development of this direct ozone measurement technique to understand P(O 3 ), especially under high-NO x regimes.

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Section: Model Descriptionmentioning

confidence: 99%

Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range

et al. 2017

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“…Our previous photochemical box model based on the regional atmospheric chemistry mechanism (RACM) was updated to RACM2 (Goliff et al, 2013). Apparent errors in the rate coefficients of key reactions were corrected; the updated equations are (1.0 × 10 −14 )exp(-490/T) for the O 3 + HO 2 reaction, (3.2 × 10 −11 )exp(67/T) for O( 1 D) + O 2 , and (2.15 × 10 −11 )exp(110/T) for O( 1 D) + N 2 , where T is the ambient temperature in kelvin.…”

Section: Box Model Simulationsmentioning

confidence: 99%

Diagnosis of Photochemical Ozone Production Rates and Limiting Factors in Continental Outflow Air Masses Reaching Fukue Island, Japan: Ozone-Control Implications

Kanaya

Tanimoto

Yokouchi

et al. 2016

Aerosol Air Qual. Res.

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Asian continental outflow air masses reach western Japan in the springtime, carrying high levels of ozone produced over the Asian continent, and facilitating in-situ production. In this study, in-situ production was highlighted; the rate and limiting factors of net ozone production were diagnosed at Fukue Island, a remote island west of Japan, on 17 days during May-June 2009, when the continental outflow air mass arrived, using an observation-based modeling approach. The average ozone production was estimated to be 6.8 ppb per day. Information on the chemical status of the arriving air mass is important, because it affects how further ozone production in the air mass occurs after precursor addition from Japanese domestic emissions. The main limiting factor of ozone production for such air masses was usually nitrogen oxides (NO x ), suggesting that domestic NO x emission control is important in reducing further ozone production. Volatile organic compounds (VOCs) also increased the ozone production rate, and occasionally (14% of time) became the dominant controlling factor. This analysis implies that the VOC reduction legislation recently enacted by the Japanese government should be effective. VOC-limited conditions occurred particularly when the air mass traveled within 6-8 h, via the Korean Peninsula. The uncertainty in the radical chemistry mechanism governing ozone production had a non-negligible impact, but the main conclusion relevant to policy was not altered. When chain termination was augmented by HO 2 + NO/NO 2 reactions in the presence of H 2 O and by heterogeneous loss of HO 2 on aerosol particle surfaces, as recently verified or hypothesized, the daily ozone production rate decreased by up to 24%, and the fraction of hours when the VOC-limited condition occurred varied from 14% to 13-26%.

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Section: Individual Chemical Compound Categoriesmentioning

confidence: 99%

“…The RADM and RACM mechanisms are similar to SAPRC in that they represent compounds on a molar basis, although reactivity weighting is used for many compounds Stockwell et al, 1990;Goliff et al, 2013). In most cases, assignments could be made based on assignments of SAPRC model species, using methods that were reviewed and approved by Stockwell for RADM2 and Goliff and Stockwell for RACM2 (Goliff et al, 2013). Where applicable, OH radical rate constants used for SAPRC detailed model species relative to those for RADM2 or RACM2 model species were used to determine reactivity weighting factors based on the approach of Middleton et al (1990).…”

Section: Individual Chemical Compound Categoriesmentioning

confidence: 99%

Development of a database for chemical mechanism assignments for volatile organic emissions

Carter

2015

Journal of the Air & Waste Management Association

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The development of a database for making model species assignments when preparing total organic gas (TOG) emissions input for atmospheric models is described. This database currently has assignments of model species for 12 different gas-phase chemical mechanisms for over 1700 chemical compounds and covers over 3000 chemical categories used in five different anthropogenic TOG profile databases or output by two different biogenic emissions models. This involved developing a unified chemical classification system, assigning compounds to mixtures, assigning model species for the mechanisms to the compounds, and making assignments for unknown, unassigned, and nonvolatile mass. The comprehensiveness of the assignments, the contributions of various types of speciation categories to current profile and total emissions data, inconsistencies with existing undocumented model species assignments, and remaining speciation issues and areas of needed work are also discussed. The use of the system to prepare input for SMOKE, the Speciation Tool, and for biogenic models is described in the supplementary materials. The database, associated programs and files, and a users manual are available online at http://www.cert.ucr.edu/ carter/emitdb.Implications: Assigning air quality model species to the hundreds of emitted chemicals is a necessary link between emissions data and modeling effects of emissions on air quality. This is not easy and makes it difficult to implement new and more chemically detailed mechanisms in models. If done incorrectly, it is similar to errors in emissions speciation or the chemical mechanism used. Nevertheless, making such assignments is often an afterthought in chemical mechanism development and emissions processing, and existing assignments are usually undocumented and have errors and inconsistencies. This work is designed to address some of these problems.

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The regional atmospheric chemistry mechanism, version 2

Cited by 230 publications

References 47 publications

Higher measured than modeled ozone production at increased NO<sub><i>x</i></sub> levels in the Colorado Front Range

Higher measured than modeled ozone production at increased NO<sub><i>x</i></sub> levels in the Colorado Front Range

Diagnosis of Photochemical Ozone Production Rates and Limiting Factors in Continental Outflow Air Masses Reaching Fukue Island, Japan: Ozone-Control Implications

Development of a database for chemical mechanism assignments for volatile organic emissions

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The regional atmospheric chemistry mechanism, version 2

Cited by 230 publications

References 47 publications

Higher measured than modeled ozone production at increased NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; levels in the Colorado Front Range

Higher measured than modeled ozone production at increased NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; levels in the Colorado Front Range

Diagnosis of Photochemical Ozone Production Rates and Limiting Factors in Continental Outflow Air Masses Reaching Fukue Island, Japan: Ozone-Control Implications

Development of a database for chemical mechanism assignments for volatile organic emissions

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Resources

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Higher measured than modeled ozone production at increased NO<sub><i>x</i></sub> levels in the Colorado Front Range

Higher measured than modeled ozone production at increased NO<sub><i>x</i></sub> levels in the Colorado Front Range