Internal consistency of the Regional Brewer Calibration Centre for Europe triad during the period 2005–2016

León-Luis, Sergio Fabián; Redondas, Alberto; Carreño, Virgilio; López-Solano, Javier; Berjón, Alberto; Hernández-Cruz, Bentorey; Santana-Díaz, Daniel

doi:https://doi.org/10.5194/amt-11-4059-2018

Articles | Volume 11, issue 7

https://doi.org/10.5194/amt-11-4059-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Quadrennial Ozone Symposium 2016 – Status and trends...

https://doi.org/10.5194/amt-11-4059-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 11, issue 7

Research article

|

13 Jul 2018

Research article |

| 13 Jul 2018

Internal consistency of the Regional Brewer Calibration Centre for Europe triad during the period 2005–2016

Sergio Fabián León-Luis, Alberto Redondas, Virgilio Carreño, Javier López-Solano, Alberto Berjón, Bentorey Hernández-Cruz, and Daniel Santana-Díaz

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Final revised paper (published on 13 Jul 2018)
Supplement to the final revised paper
Preprint (discussion started on 12 Jan 2018)

Interactive discussion

Status: closed

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

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- Supplement

RC1: 'Review of AMT-2017-460', Anonymous Referee #1, 09 Feb 2018
- RC3: 'Brewer #017', Vladimir Savastiouk, 09 Feb 2018
  - AC5: 'Reply to Referee 1 about its question about the World Triad Reference and Brewer 017', Sergio Fabián León Luis, 14 Apr 2018
- AC1: 'Reply to Referee1', Sergio Fabián León Luis, 14 Apr 2018
RC2: 'Review of RBCC-E triad stability paper', Vladimir Savastiouk, 09 Feb 2018
- AC4: 'Reply to V. Savastiouk', Sergio Fabián León Luis, 14 Apr 2018
RC4: 'Regional Brewer Calibration Centre', Tom McElroy, 13 Feb 2018
- AC2: 'Reply to Tom McElroy', Sergio Fabián León Luis, 14 Apr 2018
AC3: 'Reply to V. Savastiouk', Sergio Fabián León Luis, 14 Apr 2018

Peer-review completion

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

AR by Sergio Fabián León Luis on behalf of the Authors (14 Apr 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (24 Apr 2018) by Wolfgang Steinbrecht

RR by Anonymous Referee #1 (04 May 2018)

Suggestions for revision or reasons for rejection

Second Review AMT-2017-460

General Comments:

My first impression reading the first pages of the manuscript was, that its rewriting significantly improves not only the English but also the content and structure. All addressed issues in the first review(s) have been incorporated. Abstract and introduction are now in an acceptable form. However, coming to chapter 2, 3 and 4 more and more still unsatisfying issues showed up. Thus I am not able to recommend now its publication without further major revision.

Description of the data retrieval and Langley calibration method (chapter 2) and of the selected data sets (chapter 3) is still not perfect, but better than in the first version and more or less acceptable with some minor corrections. Chapter 4 is still difficult to read and it is hard to understand the presented findings and conclusions. Some sentences are confusing, some statements do not reflect the results (e.g. p13, l 5 and figure: no seasonal component in the relative standard deviation is in my opinion a very optimistic statement).

In addition results of the regular standard lamp tests of the Brewers are missing, which are normally a good indicator of the stability of the instrumental calibration (sorry that I did not mention this issue in my first review). A comparison of these measured SL-test records with the presented statistical parameters should be included and hopefully show the same good stability.

Chapter 5 Conclusion is a little on the short side and especially the statement in the last sentence is based mainly on one mention of the 0.5%-agreement of BR17 and BR185 (P3, l 12) during some campaigns. The results in the tables (especially table 6) only show the internal consistency within the Brewers of the various triads and that their long term stability is good. But it does not say anything about their accuracy and the comparability of the triads’ calibration levels, which is a condition for the traceability of the ozone measurements all around the world, when different triads are used for calibration of the field instruments in the global network.

Specific Comments (recommended text in “text”:
- P2, l10: This instrument is mounted on an azimuth tracker “and instead that” determines the TOC……..

- P2, l13 - 14: better “1985), it has been subjected on-going technical improvements to enhance its accuracy”.

- P2, l14 – 15: no complete sentence.

- P2, l28: replace manufacturer by with “by manufacturer”.

- P3, l3: “is used for developing and tests”.

- P3, l12: “in these comparisons”.

- P3, l13: what kind of range? SZA!

- P3, l17/18: “Moreover, in order to obtain ozone values with higher accuracy, the RBCC-E advises on the need to reprocess the preceding observation records of each Brewer at its local station”.

- P3, l20/21: no complete sentence. Perhaps it would be nice to mention ATMOZ already here in the context of Absolute Calibration Campaigns of the Brewer and Dobson reference instruments.

- P3, l33 – 34: not a good English sentence.

- P4, l4: “includes”

- P4, l11: “< 5 D.U.”.

- P5, l1: “the measured intensities Fi in raw counts for each wavelength i”.

- P5, l24: The Langley technique is most popular only for reference instruments’ calibration, but not for field instruments.

- P5 – P6 general statement: description is still not perfect, but better than the first version, therefore generally acceptable.

- P6, l14: (2 Langley “plots” per day).

- P6, l15 ff: Meaning of bullet point 3 is not clear. Normally a regular Brewer TOC observations is calculated as average out of 5 single measurements and can be used if the standard deviation is less than 2.5 D.U. What is meant with individual measurements? These do not have a standard deviation.

- P6, l17 ff: Bullet point 4: Misleading formulation, as this daily standard deviation limit of 2.5 D.U. does not come from the description under bullet point 3, which refers to individual observations.

- P6, l24/25: Wording Only when the instruments recalibrates is uncommon. I would say “changing only when the calibration of the instrument drifts”.

- General comment on the above discussed section: Here it would be proper to mention the SL-test as a simple alternative to monitor the instrument’s calibration level.

- P7, Figure 2: Error bars hardly discernible, quality of the graph is not optimal.

- P8, l4: add “Saharan” dust

- P8, l15 ff: Construction of this sentence is not good.

- P11, l5: “daily” mean?

- P11, l15 – 23: Sorry but I have problems to understand the conclusion. Somewhat confusing!

- P12, Figure 5: more detailed caption needed. Perhaps it helps to assign the different procedures to the shown panels. For a better comparability it will be helpful to use the same y-axis maximum in all sub-graphs.

- P13, l5/figure 6on P14: It is stated there is no seasonal component in the standard deviation. This IMHO not the reality, as I can see a seasonal variation.

- P13-14, l10, table 4: The mentioned 1.1% in table 4 is not clear. How is it determined? I see only numbers less than +-1%. It is not possible for me follow the conclusion of consistency

- P13 & 14 – 15: An explanation for the higher Arosa standard deviation is given, but isn’t it the same reason for the Toronto standard deviation?

- P15, Figure 7: in figure caption please use the plural “methods” and “its micrometers” instead of their micrometers.

- P15, l3: Be more precise, as it is 36% lower than 40%.

- P16, l4: “allows to”

- P16 – 17: What about the afternoon drop in figure 8, left panel? It is not explained.

- P17: As already mentioned under general comments the conclusion is a little bit short.

- P21, references: please write “Köhler” and “Kyrö”.

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RR by Vladimir Savastiouk (07 May 2018)

ED: Publish subject to minor revisions (review by editor) (08 May 2018) by Wolfgang Steinbrecht

AR by Sergio Fabián León Luis on behalf of the Authors (12 Jun 2018) Author's response Manuscript

ED: Publish as is (23 Jun 2018) by Wolfgang Steinbrecht

AR by Sergio Fabián León Luis on behalf of the Authors (27 Jun 2018) Author's response Manuscript

Short summary

In 2003, the Regional Brewer Calibration Center for Europe (RBCC-E) was established at the Izaña Atmospheric Research Center and since 2011 the RBCC-E transfers its calibration based on Langley using travelling standard(s) that are absolutely and independently calibrated at Izaña. This work is focused on reporting on the consistency of the measurements of the RBCC-E triad (Brewers #157, #183 and #185) made during the period 2005–2016.