Fast retrievals of tropospheric carbonyl sulfide with IASI

Vincent, R. Anthony; Dudhia, Anu

doi:https://doi.org/10.5194/acp-17-2981-2017

Articles | Volume 17, issue 4

https://doi.org/10.5194/acp-17-2981-2017

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

https://doi.org/10.5194/acp-17-2981-2017

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

Articles | Volume 17, issue 4

Research article

|

28 Feb 2017

Research article |

| 28 Feb 2017

Fast retrievals of tropospheric carbonyl sulfide with IASI

R. Anthony Vincent and Anu Dudhia

Download

Final revised paper (published on 28 Feb 2017)
Preprint (discussion started on 20 Sep 2016)

Interactive discussion

Status: closed

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

- Printer-friendly version

- Supplement

SC1: 'Comments on IASI OCS data', Le Kuai, 07 Oct 2016
- AC1: 'Response to SC', R. Anthony Vincent, 10 Oct 2016
  - SC2: 'More comments following auther's reply', Le Kuai, 10 Oct 2016
RC1: 'Review', Anonymous Referee #1, 07 Oct 2016
- AC2: 'Responses will be uploaded as a supplement', R. Anthony Vincent, 23 Oct 2016
SC3: 'Comments on modelling methodology, data and references', Italia De Feis, 12 Oct 2016
RC2: 'Review', Anonymous Referee #2, 15 Nov 2016

Peer-review completion

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

AR by R. Anthony Vincent on behalf of the Authors (14 Dec 2016) Author's response Manuscript

ED: Reconsider after minor revisions (Editor review) (04 Jan 2017) by Martyn Chipperfield

Dear Tony and Anu,

I think that your paper is largely acceptable for publication in ACP, but I think that there are a couple of points which need further work/clarification.

1) Variation of OCS over land. You discuss this in some detail in Section 4.2 and acknowledge that these variations may be real, or may be related to an artefact of the retrieval (e.g. varying emissivity). However, the abstract mentions the spatial variations without any mention of possible artefacts. It is a fact that some people with only a passing interest may only read the abstract, so it needs to be an accurate summary. Therefore, I would ask you to add a sentence to the abstract which summarises these retrieval caveats.

2) Validation with observations. L. Kuai raised a couple of points about validation with other datasets which are more representative of the levels where IASI has peak sensitivity. The comparison with data such as HIPPO would be an obvious question and so you need to include in the paper (Section 5) why a direct comparison was not possible. What is your response to comparing with the annual cycle in HIPPO data from earlier years in a climatological sense? Regarding your comment about column FTIR data requiring permission from one dozen scientists. I suppose that you mean that for each NDACC station, for example, there is one PI who can provide the latest data? Older NDACC data should be available publically. You are only using 7 NOAA sites and there are NDACC sites with better coverage of species (and time periods) than others. Therefore, I don’t think that in practice it will require as many contacts as you say. Someone like Justus Notholt (Bremen), Emanuel Mahieu (Liege) or Jim Hannigan (NCAR) will be able to tell you very quickly about the best NDACC sites which have OCS data for 2014 and where to obtain it. It is a small community. It should be a simple job to add in FTIR comparisons for a similar number of stations.

Best wishes,

Martyn

Hide

AR by R. Anthony Vincent on behalf of the Authors (30 Jan 2017) Author's response Manuscript

ED: Publish as is (01 Feb 2017) by Martyn Chipperfield

AR by R. Anthony Vincent on behalf of the Authors (08 Feb 2017)

Short summary

A fast method to estimate trace gases using the IASI sensor is presented and applied to tropospheric carbonyl sulphide (OCS). This rapid approach neglects non-linear effects, which introduces an 11 % error on average when estimating OCS but is significantly faster than iterative methods. All of the IASI data from 2014 were analysed to show seasonal and spatial trends in OCS. These results were compared to ground samples taken from seven different NOAA sites across the globe.