A lead-width distribution for Antarctic sea ice: a case study for the Weddell Sea with high-resolution Sentinel-2 images

Muchow, Marek; Schmitt, Amelie U.; Kaleschke, Lars

doi:https://doi.org/10.5194/tc-15-4527-2021

Articles | Volume 15, issue 9

https://doi.org/10.5194/tc-15-4527-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/tc-15-4527-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 15, issue 9

Research article

|

28 Sep 2021

Research article |

| 28 Sep 2021

A lead-width distribution for Antarctic sea ice: a case study for the Weddell Sea with high-resolution Sentinel-2 images

Marek Muchow, Amelie U. Schmitt, and Lars Kaleschke

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Final revised paper (published on 28 Sep 2021)
Preprint (discussion started on 18 Aug 2020)

Interactive discussion

Status: closed

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

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- Supplement

RC1: 'Review of Muchow et al 2020', Anonymous Referee #1, 15 Sep 2020
- AC2: 'Reply on RC1', Marek Muchow, 27 Feb 2021
RC2: 'reviewer repport', Anonymous Referee #2, 11 Dec 2020
- AC1: 'Reply on RC2', Marek Muchow, 27 Feb 2021
EC1: 'Comment on tc-2020-222', Jennifer Hutchings, 06 Jan 2021
- AC3: 'Reply on EC1', Marek Muchow, 27 Feb 2021

Peer-review completion

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

ED: Reconsider after major revisions (further review by editor and referees) (29 Apr 2021) by Yevgeny Aksenov

AR by Marek Muchow on behalf of the Authors (22 Jun 2021) Author's response Author's tracked changes Manuscript

AR by Anna Wenzel on behalf of the Authors (20 Jul 2021) Author's response

ED: Referee Nomination & Report Request started (05 Aug 2021) by Yevgeny Aksenov

RR by Anonymous Referee #1 (09 Aug 2021)

Suggestions for revision or reasons for rejection

The authors have mostly addressed the comments made in the first round of revisions. There are some issues that still needs to be adressed.

Technical corrections
Throughout the manuscript esa -> ESA

Some of the figures are using a) and b) and some Left: Right:. Please update this for consistency.

P1 R3-4. Unclear sentence after the comma please revise.

Fig. 1. Satellite Radar -> satellite radar

P4. R3. What is suitable? Please define.

Section 2. The order in which the information is presented is a bit back and forth, the 20 images are selected (P3 R17) before the description on the criteria for the selection, e.g., cloud free and time of year, is presented on P4 R1-7. Please go through this section to ensure a logical continuation of the text. How many images were excluded as they didn’t fulfil the set criteria?

P5. R8. First two should be to.
The first two paragraphs on Page 3 section 3.2 could ideally be integrated as it is now there is a lot of backtracking.

P5 R14. Image -> images?

Figure 4 is referenced to before Figure 3 in the manuscript. Please correct. Many figures appear in the text before the actual figure is shown, sometimes this is a full page apart. Please correct.

P5 R18-19. The terminology used in part of the methods section doesn’t live up to the standard one would expect from TC. Based on section 3.1 I would say that you use a supervised Bayesian classifier with a non-parametric PDF and estimate the PDF with kernel density estimation with Gaussian kernel (also known as Parzen windows). A suggestion is to use these terms when describing the method as it’ll be easier to understand for researchers used to working with pixel-wise classification.

P6 R7-9. Open water may refreeze quickly, but this depends on the surrounding temperatures. Please update the sentence.

Fig. 4. The error areas indicated in this figure are not correct. What is indicated is the pixels that are nilas but are classified as open water, but not the ones that are open water that gets classified as nilas. Similarly for the nilas vs gray sea ice, and gray sea ice vs. gray-white seas ice, and gray-white sea ice vs sea ice covered with snow. Please update the figure with a complete set of errors. Moreover, there should also be a lower threshold for the OW class, as the values below approx. 0.05 are only nilas and not OW.

How were the error estimates presented in Table 2 derived, do they include the total error or only half of the errors as indicated in Figure 4?

P9 R 14. Comparably -> comparatively

P9R14. What is this sentence referring too? The separation between open water and nilas?

P9R16. …thresholds (0.10 for OW and 0.16 for OWN) were used for the lead detection and agree with values from previous…

P10 R6-8. Do you mean that you measured leads with a width from 10m and upwards?

P10 R9. What do you mean with feature? Please clarify.

P11 R2-3. Why would leads with OWN be wider?

P13 R12. Which Landsat?

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ED: Publish subject to technical corrections (17 Aug 2021) by Yevgeny Aksenov

AR by Marek Muchow on behalf of the Authors (27 Aug 2021) Author's response Manuscript

Short summary

Linear-like openings in sea ice, also called leads, occur with widths from meters to kilometers. We use satellite images from Sentinel-2 with a resolution of 10 m to identify leads and measure their widths. With that we investigate the frequency of lead widths using two different statistical methods, since other studies have shown a dependency of heat exchange on the lead width. We are the first to address the sea-ice lead-width distribution in the Weddell Sea, Antarctica.