the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 01 Apr 2026
Antarctic Sea Ice Variations and Their Linkages with Global Extreme Weather Events
Abstract. Antarctic sea ice is a critical indicator of global climate dynamics, yet its post-2015 accelerated retreat and links to extreme weather/key climate modes remain insufficiently characterized. To address these gaps, we analyse 2010–2024 multi-source data (NSIDC sea ice extent (SIE), CMA extreme weather records, NOAA ENSO indices) via spatiotemporal decomposition, non-linear modelling, and mechanistic dissection. Antarctic SIE showed a "stable-then-decline" trend: minimal variability 2010–2014 (peak: 20.16 × 10⁶ km², Sep 2014), followed by unprecedented post-2015 retreat to a Feb 2023 historic minimum (1.85 × 10⁶ km², ~20 % below 2010–2014 summer mean). The Amundsen–Bellingshausen Sea and Antarctic Peninsula were main retreat zones, with 2020–2024 declines (10–15 %/20–25 % winter/summer) exceeding East Antarctica (5–10 %) and Ross Sea (8–12 %). We identified tiered negative covariance between SIE and extreme weather, presumably co-modulated by the El Niño-Southern Oscillation (ENSO) and Southern Annular Mode (SAM): strong associations (R² ≥ 0.6, P < 0.001) for extreme heat (400 % frequency increase) and cold waves (700 % increase), potentially via albedo–circulation feedback; moderate associations (0.5 ≤ R² < 0.6, 0.001 ≤ P < 0.01) for floods/rainstorm/typhoons, likely from ACC heat transport changes and convective propagation; weak associations (R² < 0.4, P ≈ 0.05) for blizzards, possibly due to spatially constrained El Niño–SAM effects. La Niña-positive SAM may have amplified these linkages (e.g., 400 % extreme heat increase in 2021–2023 triple La Niña), while El Niño-negative SAM suppressed them. These findings advance polar-low latitude coupling understanding, aiding extreme weather prediction and IPCC AR6-aligned adaptation.
- Preprint
(3423 KB) - Metadata XML
- BibTeX
- EndNote
Status: open (until 12 Jul 2026)
- RC1: 'Comment on egusphere-2025-6301', Anonymous Referee #1, 28 May 2026 reply
-
RC2: 'Comment on egusphere-2025-6301', Anonymous Referee #2, 09 Jun 2026
reply
GENERAL COMMENTS
This study looks at the linkages between Antarctic sea ice extent and a wide range of extreme events globally. The main results as stated in the abstract are 1) a summary of regional changes in sea ice 2) statistical relationships between Antarctic sea ice and global extremes and 3) the modulation of this relationship by ENSO and SAM. There exist robust physical arguments why certain extremes may be modulated by Antarctic SIE - for example, local storms due to heat fluxes, or conditions in Southern Hemisphere continents due to modulation of the jet stream- and why SIE might modulate global temperature via the albedo feedback effect, and these form the foundation of hypotheses in the paper. The extent to which there is evidence for these linkages is a matter of great topical interest.
However, it is a more extraordinary claim that the number of global (rather than, say, regional or southern hemisphere) extremes might be modulated to any meaningful extent by Antarctic SIE, and the evidence presented in this paper is far insufficient to support this claim. My main concerns about the analysis and conclusions are:
- The analysis (Section 3.2) is correlations between global extremes indices and SIE using an exponential regression model. There are only 14 years of data and the justification for the exponential regression model is weak; I agree relationships would not be linear necessarily, but why exponential? This is an insufficient foundation for the claims made.
- Secondly, even if the significance of this regression model is being treated appropriately, correlation is not causation. Statements such as ‘the reduction in SIE is likely a significant driver’ are used frequently; the premise seems to be that SIE drives an impact and that impact is modulated by ENSO. However, a more plausible argument based on the literature and our prior understanding is that, to first order, ENSO modulates both SIE and the many global extremes indices listed. The ENSO-Sea Ice literature is insufficiently cited.
I also have severe concerns about the literature review and mechanistic discussion. First, and most importantly, six of the references do not seem to exist. If I had realised this before reviewing the paper I would not have proceeded to review in such detail as it implies AI hallucination. These are listed below. Regardless of this, and giving the authors the benefit of the doubt, several statements are made which are not supported by the cited literature, and the literature which is cited has many omissions. Please see my specific comments. Furthermore, there is a mechanistic discussion of the linkages when statistical significance is found, but these are written as if they assume causation. Even where literature exists, it is sometimes misrepresented (e.g. Arctic papers are cited but the Antarctic is being discussed) and many of the arguments are hurried. Conclusions in the mechanistic discussion are overly confident; it makes statements as fact, rather than plausible hypothesis, and the way the literature is cited is misleading and attempts to lend more support to the current hypothesis than exists. One example is lines 364-366: “This warming effect propagates through atmospheric circulation to mid- and low-latitudes, resulting in a 37% increase in global extreme heat frequency in 2024 compared to the 2010–2020 average (Jha et al., 2025; Ji et al., 2023)” (similar to d). I think the word ‘resulting’ implies that the previous authors examined the propagation of the heat, whereas they only presented the change in heat frequency. The mechanistic section is also rather long and could benefit from more focus.
In summary, this paper is not appropriate for publication. First, while the relationships presented between global extremes and Antarctic SIE are novel, the interpretation of statistical relationships based on so few data points requires extreme care and the authors have not done this. Second, the existing literature is substantially misrepresented, as outlined above. If the authors wish to re-frame and re-submit this manuscript, they need to revisit the literature carefully, including on polar-midlatitude linkages, with careful attention to which pole and which region hypotheses have been made for. I would then suggest selecting the indices for which strong physical arguments exist for a physical linkage and focussing on these, and considering carefully the evidence for the role of ENSO/SAM as a driver rather than a modulator. Narrowing the scope would enable the authors to add analysis to support their claims i.e. if it’s claimed that Antarctic SIE has driven the extremes, would a lag be expected? Would there be ways of identifying the ‘propagation of the warming effect’? They would also be able to concentrate on the mechanistic arguments for those plausible linkages.
REFERENCE LIST ISSUES
Ayres et al: incorrect DOI (correct DOI below)
Crosta et al: incorrect DOI
Cvijanovic, I., & Caldeira, K. (2015). Antarctic sea ice and climate sensitivity. Environmental Research Letters, 10(9), 094011. https://doi.org/10.1088/1748-9326/10/9/094011: DOI points to different article, named article does not seem to exist
Dou and Zhang: incorrect DOI
He et al: citation of AGU abstract, not appropriate
Hrudya et al: DOI points to different paper, named paper doesn’t seem to exist
Jeromsen et al: not relevant, not used in text
Ji et al: Global amplification….. DOI doesn’t work, paper doesn’t seem to exist
Komatsu et al, ‘Antarctic sea ice loss amplifies polar boundary layer convection…’: does not seem to exist
Osborne et al: not relevant, not used in text
Rantanen et al “Arctic amplification…” DOI does not work, article does not seem to exist
Zhang et al ‘SAM negative phase…’: DOI does not work, article does not seem to exist.
SPECIFIC COMMENTS
There is a stylistic choice which is confusing, name the use of quotation marks throughout: three examples are “small perturbations trigger large responses” L144; “stable-then-declining’ L157; “decreasing SIE leads to increased frequency of extreme events” L230. Quotation marks should generally be used only for actual quotations, and then referenced. From the style guide: “Quotations can also be used to denote an unfamiliar or newly coined term or phrase. They may also be used to introduce a term but only once at the first instance.” I do not think this generally applies here. Also from the style guide: “Italic font may be used for emphasis, although this should be used sparingly (e.g. data were almost consistent).” I suggest that the “stable-then-declining” could be highlighted in italics but otherwise all the text appearing in quotations should just be normal text.
The regional results are emphasised but do not seem to be used in the correlation analysis.
Papers which are cited (e.g. Cvijanovic, Rantanen, Ji) [where they exist] are a) rather a selective subset of a large body of literature on midlatitude linkages and b) cover the Arctic impacts on midlatitude extremes, not the Antarctic influence on global extremes. I do not know the literature exhaustively, but missing citations include the following, which may point to further papers
- https://doi.org/10.1175/JCLI-D-21-0918.1 Ayres et al, The Coupled Atmosphere-Ocean Response to Antarctic Sea Ice Loss
- https://doi.org/10.1175/JCLI-D-23-0524.1 Hay And Kushner (2024), The Relative Importance of Antarctic Sea Ice Loss within the Response to Greenhouse Warming
L16-17 and L46-47: statements are made about about decreases in SIC, it’s unclear if these are new results or cited from the literature, since they appear in the abstract and introduction
L55-63: This section conflates a) well-evidence links between regional extremes and sea ice loss and b) globally distributed extreme events. This is problematic.
L64-66: “Existing research confirms a link between Antarctic sea ice changes and global extreme weather events” this is not supported by the cited literature
L70-72: The paper points to Josey et al (2024) as a reference for western tropical Pacific temperatures and typhoon generation frequency but that paper does not cover these affects
L86: West Antarctic rainstorm: This is written with no explanation
L92: ‘overall negative correlation between sea ice and extreme climate events’: it’s not explained what this correlation is, and there is no paper cited to justify the statement that CMIP models represent it.
L120: “This data” what data?
L125: this equation makes it clear that the percentages cited throughout are indeed ‘percentage changes in SIE’ and not sea ice concentration changes. This is important and should be made clear.
L323: Cite ENSO -sea ice literature here.
Note that my comments on the mechanistic discussion (Section 3.3) are not exhaustive since by this point I had more substantial concerns about the manuscript.L526: “this study is the first to quantify the regulatory effect of the “El Niño + negative SAM phase”. Many papers consider the combined impact of ENSO and SAM on sea ice, which is relevant here. For example; https://doi.org/10.1175/JCLI-D-22-0679.1 Wang et al, The Impacts of Combined SAM and ENSO on Seasonal Antarctic Sea Ice Changes, and citations within on the combined SAM/ENSO impact on atmospheric circulation. The fourth paragraph of this paper is helpful.
Citation: https://doi.org/10.5194/egusphere-2025-6301-RC2
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 307 | 139 | 16 | 462 | 29 | 31 |
- HTML: 307
- PDF: 139
- XML: 16
- Total: 462
- BibTeX: 29
- EndNote: 31
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
This study examines Antarctic sea ice variability between 2010 and 2024, and it’s relationship to a vast number of global climate and weather processes, from storms and heat extremes to large scale systems such as the SAM and ENSO. The authors use a combination of varied sea ice data products, and statistical tests including an exponential regression model, to show the relationships. The authors find that alongside the previously observed phase changes in sea ice over the observed time period, there were extremely high correlations with extreme events globally. Results would be of interest to anyone researching the theoretical connections between sea ice and the global climate. Overall, the paper was well written with a relatively clear experiment design, however, the claims of the paper are overstated.
The manuscript presents evidence for statistical associations between declining Antarctic sea ice extent and increasing extreme weather events. However, the analyses do not appear sufficient to infer causality. In several sections, the interpretation of the regression results may overstate the strength of the conclusions, particularly given the short temporal record and the absence of a more comprehensive treatment of confounding climate drivers.
The paper has strong merit in recognising these relationships, I particularly like the schematic, and from my extensive understanding of how Antarctic sea ice may interact with the global climate, the mechanisms and relationships are not scientifically impossible, but it would need further analysis or reframing from more certain language around causality. Specifically, softening of casual language, further acknowledgment of the limitations of the correlation pathways, reframing of pathways to be more conceptual, making it clear that the study identifies patterns consistent with teleconnection mechanisms rather than proving their direct causality. The ways in which Antarctic sea ice change interacts with the global climate is an important research topic and this work adds value, but the paper is not scientifically sound enough for publication at this time.
If the paper can be turned into a more cautions, exploratory and correlation-based synthesis paper, then I suggest Revise and Resubmit, or major revisions, at the editor’s discretion.