Dynamic and thermodynamic processes related to sea-ice surface melt advance in the Laptev Sea and East Siberian Sea

Liang, Hongjie; Zhou, Wen

doi:https://doi.org/10.5194/tc-18-3559-2024

Articles | Volume 18, issue 8

https://doi.org/10.5194/tc-18-3559-2024

© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/tc-18-3559-2024

© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 18, issue 8

Research article

|

12 Aug 2024

Research article |

| 12 Aug 2024

Dynamic and thermodynamic processes related to sea-ice surface melt advance in the Laptev Sea and East Siberian Sea

Hongjie Liang and Wen Zhou

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Final revised paper (published on 12 Aug 2024)
Supplement to the final revised paper
Preprint (discussion started on 11 Dec 2023)
Supplement to the preprint

Interactive discussion

Status: closed

RC1:
'Comment on tc-2023-134.', Anonymous Referee #1, 12 Jan 2024

This study focused on melt advance in the Laptev and East Siberian seas between 1979-2018 using the passive microwave melt onset dataset. They defined melt advance as the percentage of the area that had experienced melt onset by the end of May each year. They split up these advances based on four different scenarios: fast LS, fast ESS, slow and fast and analyzed the specific SEB and atmospheric terms associated with each. This was an interesting study and I enjoyed reading it, however I think some things could be improved upon. For one, I think clouds should be included in this study as they significantly affect the shortwave and longwave radiation and might help explain some of the contradicting statements, etc (see below). I like the concept of the melt advance metric that they made up, but I would not consider it a new dataset, as they are just taking the melt onset dataset and looking at the number of pixels that experienced melt by the end of May. It does not appear to increase the predictive skill of the September sea ice extent compared to melt onset or sea ice concentration. It would also be good to include the turbulent flux terms/figures in the main body of the text and go into this a bit more. I think this paper needs a series of revisions in order for it to be accepted for publication.

Line 28: ‘over’ should be ‘cover’.

Line 38: this sentence needs a source.

Line 39: there are many factors which contribute to Arctic amplification, not just the exchange of energy from the ocean to the atmosphere.. please see Taylor et al., 2022 (Taylor, P. C., Boeke, R. C., Boisvert, L. N., Feldl, N., Henry, M., Huang, Y., ... & Tan, I. (2022). Process drivers, inter-model spread, and the path forward: A review of amplified Arctic warming. Frontiers in Earth Science, 9, 758361._)

Line 54: I would also include Markus et al., 2009 and Stroeve et al., 2014 in this list of citations.

Line 68: I wouldn’t sure the term ‘ice block’ I would use ‘the most persistent sea ice coverage…’

Line 80: Are there a lot of missing MO values in the Markus passive microwave melt onset dataset?

Line 84: Why use the OSI SAF SIC dataset? Why not the NASA team, etc?

Sentence on line 117: I think that the average MO date is also useful and will also be different every year, because it means that an earlier MO for more of the region, then this would be a similar metric to melt advance because a larger area would have melted In possibly May. The average MO is also date dependent.

Line 227: couldn’t you see this with the latent heat flux anomalies? This might be useful to include or yo discuss more.

Paragraph beginning on Line 252: Can you say anything about the atmospheric state during the years with the strong NSR ? Are there significantly less clouds during those times which is also driving the increase in shortwave into the surface? I think this needs to be addressed as well. I assume in the years with increased water vapor and humidity that there are more clouds associated with this as well. I know you say the albedo increases due to the increase in sea ice concentration which makes sense, but also during these slow melt advance years, are there any fresh snowfall events which would increase the albedo?

Line 263: Please cite these studies that have shown this.

Paragraph on line 258: I am confused by how a warm and wet atmospheric environment could also have higher solar radiation. Normally a wet atmospheric is accompanied by more clouds and increased downwelling longwave radiation, so even if the albedo is lowered it might not offset the decrease in incoming shortwave radiation due to increased clouds.

Figure 5: Perhaps adding in the correlation coefficient on each graph would be helpful.

Figure 7: what are the pink and yellow dots? A more descriptive figure caption is needed.

Citation: https://doi.org/10.5194/tc-2023-134-RC1
- AC1: 'Reply on RC1', Hongjie Liang, 22 Feb 2024
  
  Thanks for the constructive comments from this referee. Please see reply in the attached file.
  
  Citation: https://doi.org/10.5194/tc-2023-134-AC1
RC2:
'Comment on tc-2023-134', Anonymous Referee #2, 23 Jan 2024

Publisher’s note: the supplement to this comment was edited on 25 January 2024. The adjustments were minor without effect on the scientific meaning.
The authors introduce a novel measure of the state of spring sea ice melt - Melt Advance (MA). Four scenarios of melt advance in the Laptev (LS) and East Siberian (ESS) seas are identified. For each scenario, a composite map and atmospheric parameters and sea ice concentration are derived. Based on the composite analysis authors conclude that “each scenario is driven by a distinct circulation of the low atmosphere in May”. The identification of four scenarios of melt advance in the Laptev (LS) and East Siberian (ESS) seas is a valuable contribution. However, I find that the current results and their interpretation do not robustly support the conclusion drawn in the paper. Please see my comments in the attached document.

Citation: https://doi.org/10.5194/tc-2023-134-RC2
- AC2: 'Reply on RC2', Hongjie Liang, 22 Feb 2024
  
  Thanks for the insightful comments from this referee. Please see reply in the attached file.
  
  Citation: https://doi.org/10.5194/tc-2023-134-AC2

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

ED: Reconsider after major revisions (further review by editor and referees) (01 Mar 2024) by Christian Haas

AR by Hongjie Liang on behalf of the Authors (07 Apr 2024) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (14 Apr 2024) by Christian Haas

RR by Anonymous Referee #2 (26 Apr 2024)

RR by Anonymous Referee #3 (25 May 2024)

Suggestions for revision or reasons for rejection

I am looking at this manuscript after a first round of revisions and did not review the original manuscript; therefore, I am focusing my attention on the comments from the previous reviewers and how whether the manuscript changes adequately address those concerns. The short answer: I think this paper could be a valuable contribution to The Cryosphere, but I also think there are still necessary revisions, both to bolster the most novel aspect and to refine the physical interpretations improved upon following the first round of revisions.

ISSUE A: Is it novel enough? Both reviewers commented on the melt advance metric being a positive aspect of this paper – since it is a different way of presenting melt onset data. But whether this metric provides notable gains in predictability was questioned.

I don’t see notable strides in understanding of the physical drivers of melt onset in the Laptev and East Siberian Seas. Two previous papers by the lead author already cover this extensively (Liang and Su, 2021; Liang and Zhou 2023), as does other literature (e.g., Mortin et al., 2016; Horvath et al., 2021). Therefore, I think the “novelty” aspect of this paper hinges on the potential for melt advance to be a better predictive metric than average melt onset for summer sea ice conditions.

Digging deeper into that aspect, the authors make a solid argument that it is better to have a metric that can be reliably defined on the same date every year. Otherwise, there is uncertainty over when a prediction can be made. Therefore, if melt advance on May 31 (or some other date) performs at least as well as average date of melt onset, the authors can justify melt advance as superior. The problem is that the authors do not compare the predictive skill of melt advance to the predictive skill of the average day of melt onset. Instead, they compare to the skill of May SIC. That’s not a bad comparison, to be clear, and I’d keep it. **However, I think they also need to compare melt advance’s skill to the skill of the average day of melt onset in order to make the point.**

ISSUE B: Have reviewer concerns about the physically interpretations been adequately addressed? Reviewer 1 wanted more detailed analysis of the surface energy balance – namely, including cloud cover in the analysis and looking at the individual components of the SEB more closely. They specifically wanted turbulent heat fluxes in the main body of the paper. Both reviewers expressed doubts about some of the physical interpretations.

The easy part is that the authors have included more detail from the ERA-5 data. It’s primarily in the supplemental, but it is there. The fact that cloud cover in spring is not all that variable, but total column water vapor is, aligns with my expectations. Several places that reviewers noted as problematic have been improved. There are four points, though, that I think still need revision.

1) For the polynya and the LS-faster case, there is a problem with the explanation that westerly winds would enhance polynya presence. If we look back at Figure 1 of Krumpen et al. (2011), they show several polynya areas in a U-shaped within the Laptev Sea (between Severnaya Zemlya and the New Siberian Islands). A westerly wind would indeed be offshore for the west side of this U-shape (i.e., the Eastern Severnaya Zemlya polynya, the Northeast Taymyr polynya, and the Taymyr polynya). However, for the New Siberian polynya, on the east side of that U shape, a westerly wind would be blowing against the fast ice locked in around the New Siberian Islands. That said, I agree that in the current manuscript, Figure 3 does show negative anomalies in SIC for the entirety of the polynya area for the LS-faster case. But the westerly wind explanation is not entirely satisfactory.

2) Later, on Lines 254-256, the authors talk about the how the circulation anomaly “pushes sea ice against the southern coast”. That’s true enough in the western half of the Laptev Sea, but in the eastern half, it’s really against the fast ice (although still preventing polynya formation).

3) Figure 4 shows that no anomaly extends beyond the interannual standard deviation for the ESS for the ESS-faster, LS-faster, or fast scenarios. The authors spend ample time discussing differences in the ESS for the ESS-faster scenario, but if the anomalies are no bigger than normal noise, that makes the analysis seem like over-interpretation. This limitation needs to be at least acknowledged. Perhaps there is more than one atmospheric set up that can lead to the LS-faster or ESS-faster regimes. Perhaps it’s too random or there’s too much noise from measurement errors to see clearer signals.

(This issue less problematic for slow v. fast, where we’re looking at climate change rather than internal variability, and the LS shows more notable differences.)

4) Figure 5 also has a statistical issue. The second and third plots in the bottom row for ESS are clearly affected by a single outlier with excessive leverage. The relationships would be different if that outlier were removed – perhaps substantially different.

ISSUE C: Finally, this wasn’t brought up by prior reviewers, but I don’t think the Figure 7 schematic is worth it for the manuscript. The words in the text do a much better job summarizing conclusions and the schematic is difficulty to see and read. It’s a cool idea, but there’s just too much being incorporated for me to see much value. On a poster, where it could be bigger, I think it would work better.

References
Horvath, S., Stroeve, J., Rajagopalan, B., and Jahn, A.: Arctic sea ice melt onset favored by an atmospheric pressure pattern reminiscent of the North American-Eurasian Arctic pattern, Climate Dynamics, 57, 1771-1787, 10.1007/s00382-021-05776-y, 2021.
Krumpen, T., Hölemann, J. A., Willmes, S., Morales Maqueda, M. A., Busche, T., Dmitrenko, I. A., Gerdes, R., Haas, C., Heinemann, G., Hendricks, S., Kassens, H., Rabenstein, L., and Schröder, D.: Sea ice production and water mass modification in the eastern Laptev Sea, Journal of Geophysical Research, 116, 10.1029/2010jc006545, 2011.
Liang, H. and Su, J.: Variability in Sea Ice Melt Onset in the Arctic Northeast Passage: Seesaw of the Laptev Sea and the East Siberian Sea, Journal of Geophysical Research: Oceans, 126, e2020JC016985, 10.1029/2020JC016985, 2021.
Liang, H. and Zhou, W.: Arctic Sea Ice Melt Onset in the Laptev Sea and East Siberian Sea in Association with the Arctic Oscillation and Barents Oscillation, Journal of Climate, 36, 6363-6373, 10.1175/jcli-d-22-0791.1, 2023.
Mortin, J., Svensson, G., Graversen, R. G., Kapsch, M.-L., Stroeve, J. C., and Boisvert, L. N.: Melt onset over Arctic sea ice controlled by atmospheric moisture transport, Geophysical Research Letters, 43, 6636-6642, 10.1002/2016GL069330, 2016.

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ED: Reconsider after major revisions (further review by editor and referees) (26 May 2024) by Christian Haas

AR by Hongjie Liang on behalf of the Authors (03 Jun 2024) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (15 Jun 2024) by Christian Haas

RR by Anonymous Referee #3 (24 Jun 2024)

ED: Publish as is (30 Jun 2024) by Christian Haas

AR by Hongjie Liang on behalf of the Authors (01 Jul 2024)

Short summary

This study identifies the metric of springtime sea-ice surface melt advance in the Laptev Sea and East Siberian Sea, which can be defined on the same date each year and has the potential to be used in the practical seasonal prediction of summer sea ice cover instead of average melt onset. Detailed analysis of dynamic and thermodynamic processes related to different melt advance scenarios in this region imply considerable interannual and interdecadal variability in springtime conditions.