VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China

Huang, C.; Wang, H. L.; Li, L.; Wang, Q.; Lu, Q.; de Gouw, J. A.; Zhou, M.; Jing, S. A.; Lu, J.; Chen, C. H.

doi:https://doi.org/10.5194/acp-15-11081-2015

Articles | Volume 15, issue 19

https://doi.org/10.5194/acp-15-11081-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/acp-15-11081-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 15, issue 19

Research article

|

06 Oct 2015

Research article |

| 06 Oct 2015

VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China

C. Huang, H. L. Wang, L. Li, Q. Wang, Q. Lu, J. A. de Gouw, M. Zhou, S. A. Jing, J. Lu, and C. H. Chen

Download

Final revised paper (published on 06 Oct 2015)
Supplement to the final revised paper
Preprint (discussion started on 17 Mar 2015)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC C1559: 'Review of Huang et al', Anonymous Referee #1, 14 Apr 2015
- AC C4510: 'Response to C1559', C. Huang, 08 Jul 2015
RC C1772: 'review', Anonymous Referee #2, 21 Apr 2015
- AC C4548: 'Response to C1772', C. Huang, 08 Jul 2015

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by C. Huang on behalf of the Authors (14 Jul 2015) Author's response Manuscript

ED: Referee Nomination & Report Request started (20 Jul 2015) by John Liggio

RR by Anonymous Referee #2 (30 Jul 2015)

Suggestions for revision or reasons for rejection

The authors have addressed many of my main comments. Some of the main points still need better justification. Also, the writing and structure still remains confusing at times. I think this paper should undergo one more round of revision, before being reconsidered.

Following up on my previous comments:
1. Regarding the IVOCs, the authors have addressed the missing IVOC measurements by inferring the volatility distribution of exhaust based on literature. While this approach is speculative, there is still utility in conducting this analysis as a sensitivity study. I just have two suggestions:
a) These estimations should be referred to as "inferred", not "literature" or "references". For example, in line 13 of the abstract, the "references IVOC species" should be "inferred carbon number distributions".
b) Readers should be cautioned these are inferred distribution only. I suggest showing the fraction of SOA (or contribution to yield) from these inferred IVOCs in Fig. 5. I also suggest showing the uncertainty in deltaOA/deltaCO as a result of this assumption. (e.g. show deltaOA/deltaCO with and without these inferred IVOCs)

2. Line 316-323: the authors used the urban vehicular fraction of CO emissions instead of the fraction for the whole of Shanghai. They did so because their measurements were conducted in urban Shanghai. This might not be a correct assumption. The authors need to show that the observed deltaCO is indeed coming from urban Shanghai only, and that CO from neighboring industrial areas will only be observed as background in the current set of measurements and are subsequently subtracted out. Based on what is shown in the manuscript, I do not agree with this assumption, since CO is a long-lived species can easily be transported between different areas of Shanghai.

Other comments:
- The abstract is full of abbreviations that are not defined (IVOCs, VKT, SOA, deltaOA/deltaCO etc.) They should be fully defined, or not used in the abstract.
- Line 68: "The number of vehicles in Shanghai was doubled..." should be "The number of vehicles in Shanghai has doubled..."
- Line 235-237: SOA yields are defined for a specific organic loading, based on semivolatile partitioning theory. Using Gentner’s yields may not be appropriate since total OA is likely higher in Shanghai than it is in LA.
- Line 278: Stating that xylene and ethylbenzene are "engaged in different chemical reactions in the day time" is misleading. They are oxidized by the same radical to form the same type peroxy radicals that lead to their decay. To be more precise, xylene and ethylbenzene are oxidized *at different rates* from each other.
- Line 430: Fig. 7 should be Fig. 6

Hide

ED: Reconsider after major revisions (31 Jul 2015) by John Liggio

AR by C. Huang on behalf of the Authors (14 Sep 2015) Author's response Manuscript

ED: Publish as is (16 Sep 2015) by John Liggio

AR by C. Huang on behalf of the Authors (18 Sep 2015)

Download

Article (1210 KB)
Full-text XML

Short summary

SOA formations from vehicle exhausts and gas evaporation contribute 40% and 60% of total organic aerosols observed in summer and winter in urban Shanghai. Diesel vehicles, which accounted for less than 20% of vehicle kilometers of travel, contribute the most to vehicular POA emissions and SOA production in urban Shanghai. Intermediate-volatile organic compounds (IVOCs) in vehicle exhausts contribute greatly to SOA formation in the urban atmosphere of China.