Understanding the relative importance of vertical and horizontal flow in ice-wedge polygons

Wales, Nathan A.; Gomez-Velez, Jesus D.; Newman, Brent D.; Wilson, Cathy J.; Dafflon, Baptiste; Kneafsey, Timothy J.; Soom, Florian; Wullschleger, Stan D.

doi:https://doi.org/10.5194/hess-24-1109-2020

Articles | Volume 24, issue 3

https://doi.org/10.5194/hess-24-1109-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/hess-24-1109-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 24, issue 3

Research article

|

10 Mar 2020

Research article |

| 10 Mar 2020

Understanding the relative importance of vertical and horizontal flow in ice-wedge polygons

Nathan A. Wales, Jesus D. Gomez-Velez, Brent D. Newman, Cathy J. Wilson, Baptiste Dafflon, Timothy J. Kneafsey, Florian Soom, and Stan D. Wullschleger

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Final revised paper (published on 10 Mar 2020)
Supplement to the final revised paper
Preprint (discussion started on 01 Apr 2019)

Interactive discussion

Status: closed

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

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- Supplement

RC1: 'Wales et al', Anonymous Referee #1, 24 May 2019
- AC1: 'Response to Anonymous Referee #1', Nathan Wales, 26 Jul 2019
RC2: 'Review of HESS-2019-25', Anonymous Referee #2, 03 Jun 2019
- AC2: 'Response to Anonymous Referee #2', Nathan Wales, 26 Jul 2019

Peer-review completion

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

ED: Reconsider after major revisions (further review by editor and referees) (09 Sep 2019) by Theresa Blume

AR by Nathan Wales on behalf of the Authors (18 Oct 2019) Author's response Manuscript

ED: Referee Nomination & Report Request started (23 Oct 2019) by Theresa Blume

RR by Anonymous Referee #1 (21 Nov 2019)

RR by Anonymous Referee #2 (09 Dec 2019)

Suggestions for revision or reasons for rejection

General comment:

This is a second review for this manuscript. In general, the authors have done an acceptable job addressing earlier comments and questions, both from me and the other reviewer. The review is primarily focused on responses to a few comments raised earlier.

Specific comments – comments called out by x/y, where x is page and y is line number in the revised manuscript.

7/1, 10/12 and elsewhere – I disagree with the authors regarding the use of the term ‘center’ versus ‘interior’ to identify tracer application, which was a point of confusion to this reviewer in the original manuscript. I don’t see the advantage in following conventional terms to describe an unconventional experiment. Indeed, had the tracer been applied to the center of the polygon, as stated in the paper, then the assumptions underlying van Genuchten and Alves solutions would be have been valid and easier to justify, rather than using the edge of the vertical cylinder that represented the edge of the application area. Using the term ‘center’ is inaccurate, regardless of whether it follows convention.

7/7 – That the ponded water didn’t exist when tracer was applied certainly simplifies the analysis, as least from the standpoint of dilution, but the basic question remains: is water content data available? If not, how was liquid-filled porosity handled in the velocity term for van Genuchten and Alves? What is the impact of partially saturated material on the vertical migration of tracer down to the ice table? How are you estimating pore water velocity?

16/21 – regarding the issue of experiment length and tracer recovery, it is indeed an unfortunate reality that funding is not infinite and neither is the time available to complete a MS thesis. That said, these two factors did impact the results of the experiments, and our understanding of how heterogeneity might impact shallow subsurface transport, by limiting the number of polygons that could be tested and by not running the experiment long enough to recover enough tracer to avoid using ~5% recover as a high estimate on the lower range. What does this mean going forward? How long should the experiment have lasted? What value could be expected by conducting a sufficiently long experiment?

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ED: Publish subject to minor revisions (review by editor) (13 Dec 2019) by Theresa Blume

AR by Nathan Wales on behalf of the Authors (18 Dec 2019)

ED: Publish subject to technical corrections (27 Jan 2020) by Theresa Blume

AR by Nathan Wales on behalf of the Authors (31 Jan 2020) Author's response Manuscript

Short summary

Rapid warming in the Arctic is causing increased permafrost temperatures and ground ice degradation. To study the effects of ice degradation on water distribution, tracer was applied to two end members of ice-wedge polygons – a ubiquitous landform in the Arctic. End member type was found to significantly affect water distribution as lower flux was observed with ice-wedge degradation. Results suggest ice degradation can influence partitioning of sequestered carbon as carbon dioxide or methane.