AMOC and North Atlantic Ocean Decadal Variability: A Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript ID: oceans-3703576

Title: AMOC and North Atlantic Ocean Decadal Variability: A Review

Authors: Seidov et al.

 

Originality: Good

Technical Quality: Good

Clarity of Presentation: Good

Significance: Good

 

Recommendation: Minor revision

This is a well-researched, clearly written, and timely review of the Atlantic Meridional Overturning Circulation (AMOC) and its decadal variability. The authors synthesize over 300 observational, modelling, and paleo-proxy studies, highlight points of consensus (e.g., a modest 20th-century weakening) and areas of active debate (e.g., tipping-point timing, freshwater versus wind-stress controls), and end with practical recommendations for future monitoring and model development. Although the manuscript is lengthy (73 pp.), it provides a valuable one-stop resource for researchers and advanced students. I recommend acceptance after minor revisions.

Major comments:

1. The review spans historical theory, modern observing systems, high-resolution modelling, and recent “early-warning” statistics, giving readers a 360-degree view of the field.
2. Conflicting evidence is presented even-handedly; the authors resist over-claiming an imminent AMOC collapse while acknowledging genuine uncertainty.
3. The feedback schematic (Fig. 17) and the timeline of AMOC monitoring arrays are particularly helpful for newcomers.
4. Technical terms are defined, acronyms kept under control, and section headings guide the reader effectively.

 

Minor suggestions:

1. At 73 pages, the paper risks overwhelming non-specialists. Consider condensing §§ 3–4 by merging sub-subsections that reiterate similar mechanisms (e.g., freshwater hosing experiments). A ~10-15 % cut would sharpen the narrative without losing content.
2. Since lots of figures are cut from other literatures, the quality is not good. Please consider to replot them using the published data.
3. A few 2024 studies on AMOC reconstructions and high-resolution CESM2 forecasts are missing (e.g., Caesar et al., Clim. Change, 2024). Adding two or three of these in § 5 would keep the review fully up-to-date.
4. Data availability: Since the paper is a review, no raw data are required, but a final paragraph with a link to the Zotero/Endnote library (if the authors keep one) would be a nice extra service to readers.

 

The manuscript is already a solid contribution; addressing the modest suggestions above will raise its clarity and presentation quality to the level expected for publication in Oceans.

 

Author Response

Response to Reviewer #1

We extend our gratitude to Reviewer #1 for their positive feedback on our work and for their helpful minor suggestions.

A key point highlighted is the specific mention of high-resolution modeling using the CESM2 climate model. To underscore the significance of high-resolution climate modeling, which has only recently become feasible with the introduction of CESM2 and other high-resolution models, we have added a paragraph and new citations (new lines 957-965).

Concerning the quality of certain figures, we attempted to resample some and believe that most are adequate to support the discussions in the text. Unfortunately, figures sourced from older publications cannot be successfully resampled and recreated due to the absence of necessary data. However, after a thorough review, we are confident that they are appropriate for this review's purpose.

Lastly, we considered shortening the manuscript by merging §§3 and 4, but this would necessitate a major restructuring of the text, and after careful consideration, we decided against such significant changes. We hope this decision does not alter the reviewer’s favorable opinion of our work.

Once more, we appreciate the time and effort Reviewer #1 has dedicated to reviewing our manuscript and supporting our work. We trust that the minor issues have now been addressed to the reviewer’s satisfaction.

Reviewer 2 Report

Comments and Suggestions for Authors

See attachment.

Comments for author File: Comments.pdf

Author Response

Please see attachment for author response to Reviewer 2.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have fully responded to my comments. I do not have questions anymore.

Reviewer 2 Report

Comments and Suggestions for Authors

I would like to thank the authors for their responses and the revisions made to the manuscript. The revised version presents a much more nuanced perspective, particularly regarding the risk of AMOC tipping during this century.

I believe that the risk of an AMOC collapse may be somewhat higher than the authors suggest. This, however, cannot be verified with the currently available data. I sincerely hope that the AMOC proves resilient under future climate change, given the potentially severe large-scale climate impacts. Nevertheless, this concern should not be seen as a reason to delay publication of this review paper.

Congratulations to the authors!