Lidar detection of high concentrations of ozone and aerosol transported from northeastern Asia over Saga, Japan

Uchino, Osamu; Sakai, Tetsu; Izumi, Toshiharu; Nagai, Tomohiro; Morino, Isamu; Yamazaki, Akihiro; Deushi, Makoto; Yumimoto, Keiya; Maki, Takashi; Tanaka, Taichu Y.; Akaho, Taiga; Okumura, Hiroshi; Arai, Kohei; Nakatsuru, Takahiro; Matsunaga, Tsuneo; Yokota, Tatsuya

doi:https://doi.org/10.5194/acp-17-1865-2017

Articles | Volume 17, issue 3

https://doi.org/10.5194/acp-17-1865-2017

© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/acp-17-1865-2017

© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 17, issue 3

Research article

|

08 Feb 2017

Research article |

| 08 Feb 2017

Lidar detection of high concentrations of ozone and aerosol transported from northeastern Asia over Saga, Japan

Osamu Uchino, Tetsu Sakai, Toshiharu Izumi, Tomohiro Nagai, Isamu Morino, Akihiro Yamazaki, Makoto Deushi, Keiya Yumimoto, Takashi Maki, Taichu Y. Tanaka, Taiga Akaho, Hiroshi Okumura, Kohei Arai, Takahiro Nakatsuru, Tsuneo Matsunaga, and Tatsuya Yokota

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Final revised paper (published on 08 Feb 2017)
Preprint (discussion started on 22 Jun 2016)

Interactive discussion

Status: closed

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

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RC1: 'Revision of Uchino et al., ACPD', Anonymous Referee #1, 26 Jul 2016
RC2: 'Review of manuscript Lidar detection of high concentrations of ozone and aerosol transported from Northeast Asia over Saga, Japan by Uchino et al.', Anonymous Referee #2, 05 Aug 2016
AC1: 'Final response', Osamu Uchino, 08 Nov 2016

Peer-review completion

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

AR by Svenja Lange on behalf of the Authors (10 Nov 2016) Author's response

ED: Referee Nomination & Report Request started (14 Nov 2016) by Yugo Kanaya

RR by Anonymous Referee #2 (28 Nov 2016)

RR by Anonymous Referee #1 (30 Nov 2016)

Suggestions for revision or reasons for rejection

In the revised version of the manuscript, a good effort has been done to improve the quality of the paper. Most of the corrections suggested were properly addressed.
Before the acceptance of the paper, I recommend to address the following two minor points:

1) The altitudes detected from the lidar measurements (shown in Fig. 11) only in some cases correspond to the atmospheric boundary layer top. For numerous profiles (e.g. from 1200 JST of 20 March to 12 00 JST of 21 March), the method detects altitudes above 2 km that are not realistic boundary layer heights for this season. The algorithm applied to lidar measurements detects vertical gradients of aerosol backscattering, thus the top of aerosol layers that may not be the boundary layer top. A physical identification of the boundary layer top is done by recognizing the temperature inversion from radiosoundings as already shown in the figure. My recommendation is to screen out all heights detected from lidar data that do not correspond to the boundary layer height shown by the radiosoundings. Also, the difference between residual layer and mixing layer does not seem to be clear in the current paper. Radiosounding can tell the location of both as below the mixing layer the profile of potential temperature is neutral above an unstable layer near the surface and the residual layer corresponds to a neutral profile above a stable layer.

2) The lidar ratio for both dust and pollution aerosols is the same (50 sr). This is an approximation as shown by the authors themselves: dust seem to have lower lidar ratios than pollution aerosol. I recommend to include in the text of the manuscript the values given in the answers to the reviewers : “Their summaries are as follows: Sakai et al.(2003): Asian dust 47±18 sr, Cattrall et al.(2005): Dust (spheroids) 42±4 sr, SE AsiaPollution 58±10 sr, Anderson et al.(2003): ACE-Asia Pollution (Fine-dominated, submicron portion) 50±5 sr, Dust (Coarse-dominated, Dust-like chemistry, Supermicron portion) 46±8 sr.” and then indicate that as a simplification, they use the same value for both species.

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ED: Reconsider after minor revisions (Editor review) (01 Dec 2016) by Yugo Kanaya

Dear Authors,

Thank you for submitting your revised manuscript. Re-evaluation was made by our two reviewers. One suggested accepted as is, and the other requested minor revision. I would appreciate you could further respond to the comments by the reviewer #2. Also, I hope if you could take into account the handling editor's comments below:

1. Although the focus of the manuscript is successfully shifted to the aspect of transport analysis, the Introduction part remained focused on the technical aspects and the authors' works. It is better to add some more general description on O3 and aerosols pollutions reaching this region in spring from the continent, citing literature (including those not using lidars), touching on what was studied before and what is yet to be analyzed (e.g., three dimensional features of ozone). This will highlight the value of this manuscript.

2. lines 150-151. Is an old-type ozone monitor based on wet chemistry is still under use at this site, where the PAN interference matters?

3. line 181. Add base year of REAS2.1 emission inventory used for modeling.

4. lines 186 and 194. How is the 20% of systematic error related to the uncertainty of 12% in line 194?

5. lines 266-267. The skyradiometer could have different sight than the lidar. This is also a possible reason for the difference.

6. line 296. When the contribution from dust particles is 100%, those from others need to be 0%.

7. Figure 8(b). There are several regions with increased dust extinction coefficient. Where do the authors think are the source regions of dust? The maximum during 1800 20 March - 0000 21 March is best connected to the increase over Saga; however, the region is over the ocean or the Shandong Peninsula and thus is not likely the source region.

Yugo Kanaya
ACP Co-Editor

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AR by Osamu Uchino on behalf of the Authors (28 Dec 2016) Author's response

AR by Svenja Lange on behalf of the Authors (04 Jan 2017) Author's response Manuscript

ED: Publish subject to technical corrections (07 Jan 2017) by Yugo Kanaya

Short summary

To validate products of GOSAT, we observed vertical profiles of aerosols, thin cirrus clouds, and tropospheric ozone with a mobile lidar system that consisted of a two-wavelength (532 and 1064 nm) polarization lidar and tropospheric ozone differential absorption lidar (DIAL). We used these lidars to make continuous measurements over Saga (33.24° N, 130.29° E) during 20–31 March 2015. High ozone and high aerosol concentrations were observed almost simultaneously and impacted surface air quality.