Atmospheric speciated mercury concentrations on an island between China and  Korea: sources and transport pathways

Lee, Gang-San; Kim, Pyung-Rae; Han, Young-Ji; Holsen, Thomas M.; Seo, Yong-Seok; Yi, Seung-Muk

doi:https://doi.org/10.5194/acp-16-4119-2016

Articles | Volume 16, issue 6

https://doi.org/10.5194/acp-16-4119-2016

© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue:

Data collection, analysis and application of speciated atmospheric...

https://doi.org/10.5194/acp-16-4119-2016

© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 16, issue 6

Research article

|

30 Mar 2016

Research article |

| 30 Mar 2016

Atmospheric speciated mercury concentrations on an island between China and Korea: sources and transport pathways

Gang-San Lee, Pyung-Rae Kim, Young-Ji Han, Thomas M. Holsen, Yong-Seok Seo, and Seung-Muk Yi

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Final revised paper (published on 30 Mar 2016)
Supplement to the final revised paper
Preprint (discussion started on 24 Nov 2015)

Interactive discussion

Status: closed

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

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- Supplement

RC C10734: 'Review of "Atmospheric Speciated Mercury Concentrations on an Island between China and Korea: Sources and Transport Pathways"', Anonymous Referee #2, 21 Dec 2015
- AC C12318: 'Response letter for the reviewer 2', Young-Ji Han, 11 Feb 2016
RC C10757: 'Review of ACPD-15-32931-2015', Anonymous Referee #1, 22 Dec 2015
- AC C12317: 'response letter for the reviewer 1', Young-Ji Han, 11 Feb 2016

Peer-review completion

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

AR by Young-Ji Han on behalf of the Authors (11 Feb 2016) Author's response Manuscript

ED: Referee Nomination & Report Request started (12 Feb 2016) by Leiming Zhang

RR by Anonymous Referee #1 (21 Feb 2016)

RR by Anonymous Referee #2 (26 Feb 2016)

Suggestions for revision or reasons for rejection

The revised paper has improved compared to the discussion paper. However, there are some uncertainties that should be emphasized in the revised paper.

Specific comments:
Line 186: Using 12 trajectories to represent one GOM or PBM measurement is a large source of uncertainty. Simply mentioning that other studies had done the same thing doesn’t address the uncertainties in this current study. The trajectory directions can change significantly over a 12 hr period, but this variation is not reflected in the GOM and PBM measurements. More discussion is needed on how these uncertainties would affect the PSCF results.

Lines 189-190: I suggest not using “successful” because the modeled sources haven’t been evaluated.

Line 211: Similar to the above comment, using 12 wind directions to represent one GOM and PBM concentration is a large source of uncertainty. Wind directions can change significantly over a 12 hr period but you wouldn’t know the impact to GOM or PBM because there is only one measurement. More discussion is needed on how these uncertainties would affect the CPF results.

Lines 295-297: The partial correlations from multiple linear regression should be reported. This gives the unique contribution of each independent variable to Kp. It’s not the same as performing two separate linear regressions for temperature and RH.

Line 303: What was the goodness of fit (R2) for this equation? Gas-particle partitioning models developed in other studies should be mentioned in the results as well. The studies below were able to obtain a higher R2 and validated the model with Kp data at other sites.

Rutter, A. P., & Schauer, J. J. (2007). The effect of temperature on the gas–particle partitioning of reactive mercury in atmospheric aerosols. Atmospheric Environment, 41(38), 8647-8657.
Cheng, I., Zhang, L., & Blanchard, P. (2014). Regression modeling of gas‐particle partitioning of atmospheric oxidized mercury from temperature data. Journal of Geophysical Research: Atmospheres, 119(20), 11864-11876.

Line 404: Uncertainties related to different aerosol composition and temperature with different wind directions needs to be mentioned here. Both of these factors can affect gas-particle partitioning, which in turn affects Kp or the GOM/PBM ratio.

Lines 486-488: These results could be very different using the median concentration for each cluster. If the mean and median concentration for each cluster varies significantly, the source contribution results would likely be very different. In this case, which measure is most representative of the concentration for each cluster and should be used to determine the source contributions?

Lines 466-476: The results here are very inconsistent. Line 466 states, “Compared to the other clusters, the source contributions of clusters 1 and 4, which represent regional transport, were relatively low for all Hg species (Table 4). Cluster 5 contributed more significantly, especially for GOM and PBM, indicating the importance of Korean sources.” Later on line 475 states, “Clusters 1 and 5 were used to represent the effect of sources outside of Korea and the cluster 4 was used to indicate the effect of sources in Korea.”

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ED: Reconsider after minor revisions (Editor review) (01 Mar 2016) by Leiming Zhang

AR by Young-Ji Han on behalf of the Authors (10 Mar 2016) Author's response Manuscript

ED: Publish as is (10 Mar 2016) by Leiming Zhang

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Short summary

This study was initiated to identify the sources affecting speciated mercury concentrations measured on the island located between mainland Korea and China. The results from various approaches consistently show that Korean sources are most important for gaseous oxidized form while for other Hg species regional transport was also important. It is also suggested that the secondary formation of particulate Hg becomes more important as the significance of long-range transport increased.