Dust–air pollution dynamics over the eastern Mediterranean

Abdelkader, M.; Metzger, S.; Mamouri, R. E.; Astitha, M.; Barrie, L.; Levin, Z.; Lelieveld, J.

doi:https://doi.org/10.5194/acp-15-9173-2015

Articles | Volume 15, issue 16

https://doi.org/10.5194/acp-15-9173-2015

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

Special issue:

The Modular Earth Submodel System (MESSy) (ACP/GMD inter-journal...

https://doi.org/10.5194/acp-15-9173-2015

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

Articles | Volume 15, issue 16

Research article

|

19 Aug 2015

Research article |

| 19 Aug 2015

Dust–air pollution dynamics over the eastern Mediterranean

M. Abdelkader, S. Metzger, R. E. Mamouri, M. Astitha, L. Barrie, Z. Levin, and J. Lelieveld

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Final revised paper (published on 19 Aug 2015)
Supplement to the final revised paper
Preprint (discussion started on 11 Mar 2015)

Interactive discussion

Status: closed

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

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- Supplement

RC C2343: 'anonymous review', Anonymous Referee #1, 07 May 2015
- AC C3527: 'Reply to Referee #1', Mohamed AbdelKader, 12 Jun 2015
RC C2392: 'Review of the manuscript entitled: Dust-Air Pollution Dynamics over the Eastern Mediterranean by Abdelkader et al.', Anonymous Referee #2, 08 May 2015
- AC C3528: 'Reply to Referee #2', Mohamed AbdelKader, 12 Jun 2015

Peer-review completion

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

AR by Anna Wenzel on behalf of the Authors (16 Jun 2015) Author's response

ED: Referee Nomination & Report Request started (16 Jun 2015) by Maria Kanakidou

RR by Anonymous Referee #1 (21 Jun 2015)

Suggestions for revision or reasons for rejection

The authors did a lot to improve the paper. I am very pleased with all the changes.

But there seems to be something wrong regarding the link between the mass concentrations the authors present and the optical properties (AOD, extinction coefficient). This was already the case in the submitted version, but I did not notice that because of all the other aspects I had to think about.

Now the authors include dust extinction profiles (Fig.10) and the comparisons between observations and modeled profiles agree reasonably well.

But from the dust extinction coefficients (max. values of 0.3 km-1 or 300 Mm-1, e.g., in Fig.9) I would expect dust mass concentrations up to 600 micrograms per m3, but in their paper they only have maximum dust concentrations of about 5-7 micrograms per m3. The same with the column dust mass concentration of 5 mg/m2 (presented). Realistic values would be 500 mg /m2 for huge dust outbreaks. So, there are deviations by a factor of 100 (two orders of magnitude).

For comparison: In Fig.3, the total PM is 10-20 micrograms per m3 at Agia Marina (background site), for a typical 500 AOT values around 0.05 to 0.1 (I speculate). Taking a PBL height of 1 km into account we have particle extinction coefficients of about 0.05-0.1 km-1 or 50-100 Mm-1. The volume-to-extinction conversion factor is 0.2 for fine mode dominated particle ensembles according to AERONET products. So this relationship makes roughly sense, when assuming a particle density of 1.6 g/cm3.

For coarse mode aerosol, the volume-to-extinction conversion is 0.8 *1e-6 m (multiplied by a dust density of 2.6 g cm-3 ) we end up with a conversion factor of 2 (from extinction in Mm-1 to mass conc. in micrograms per m3).

Therefore, if a huge dust outbreak is observed (29 Sep) with AOT of the order of 0.2 to 0.4 and extinction values up to 300 Mm-1 (in Fig.9), the dust mass concentration cannot be 1 micrograms per m3 (a factor of 10 lower than the background PM at Agia Marina)!

Please check all the steps in your model from microphysical properties to optical properties…. as mentioned, the optical properties seem to be ok! They are in agreement with AERONET and Limassol lidar.

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ED: Reconsider after minor revisions (Editor review) (12 Jul 2015) by Maria Kanakidou

AR by Mohamed AbdelKader on behalf of the Authors (22 Jul 2015) Author's response Manuscript

ED: Publish subject to technical corrections (06 Aug 2015) by Maria Kanakidou

AR by Mohamed AbdelKader on behalf of the Authors (10 Aug 2015) Author's response Manuscript

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