| 02 Sep 2026
Drivers of Spatially Heterogeneous Changes in Summertime Sea Ice Variability in the Weddell Sea
Abstract. Interannual variability of Antarctic sea ice has undergone substantial changes in recent decades, particularly in the Weddell Sea. Previous study examined the change in interannual variability of sea ice extent (SIE) in the Weddell Sea. However, the spatial characteristics and driving mechanisms of changes in sea-ice concentration (SIC) interannual variability within the Weddell Sea remain insufficiently understood. Here, we investigate changes in austral summer (January–March) interannual SIC variability in the Weddell Sea during 1979–2024. The results reveal a distinct dipole pattern, characterized by increasing interannual variability in the northern Weddell Sea and decreasing variability in the southern Weddell Sea. Enhanced convective activity over eastern Australia and the southern Indian Ocean excites separate Rossby wave trains that propagate into the Southern Ocean and generate opposite zonal pressure gradients over the Weddell Sea. The resulting anomalous northerly (southerly) winds promote sea ice convergence and increased sea-ice concentration in the southern (northern) Weddell Sea, thereby contributing to reduced (enhanced) interannual sea-ice variability.
Review of “Drivers of Spatially Heterogeneous Changes in Summertime Sea Ice Variability in the Weddell Sea” by Yu et al.,
General comments
I found that the topic of this manuscript fits well within the scope of The Cryosphere (TC) Journal. My first impression is that the manuscript in its current form is not suitable for publication as a full research paper. The manuscript is quite brief and lacks sufficient details. The current presentation is primarily descriptive; the authors process several data sets and describe the trends and statistical metrics obtained from the figures, but a deeper interpretation of the results and a robust discussion of the underlying mechanisms are not presented.
Although the title claims to address the “Drivers of Spatially Heterogeneous Changes,” I found no adequate discussion of these spatial heterogeneity changes within the manuscript at all. Instead, the authors largely focus on the contrasting trends observed between the northern and southern Weddell Sea and the impact of large-scale atmospheric circulation on sea ice. The latter aligns well with existing research methodologies. To fit the manuscript title, the authors need to add a comprehensive discussion on the “spatial heterogeneity changes” of summer sea ice in the Weddell Sea.
“using a newly developed variance-trend diagnostic method”: What is this method?
The results chapter is too simple. It basically explains the figures.
Several details:
L83-84: “and sea ice dynamic and thermodynamic variables.” What are those variables?
L84-86: “Together, these datasets provide a comprehensive framework for examining atmosphere–ocean–sea ice interactions associated with interannual sea ice variability in the Southern Ocean”. How? Please describe how those datasets can capture the spatial heterogeneity changes of summer sea ice in the Weddell Sea. What are the resolutions of those datasets? What is the spatial scale of the “spatial heterogeneity changes”?
L104-106: “In this study, interannual variability is defined as variability with periods 2-9 years.” What does it mean?
“The resulting variance fields are used to evaluate both temporal trends and spatial patterns of sea ice variability across the Weddell Sea.” How can the “variability with periods 2-9 years” be used to evaluate the spatial patterns?
Figure 1: It is very difficult for readers who are not familiar with Antarctica to understand where the Weddell Sea is located.
Figures S1a and S1b: I can find those figures
L172: (Yu et al., 2026): I can’t find it in the list of references
L229: Yu et al. (2026b): I can’t find it in the list of references
L263: “The code is available on request from the corresponding author.” a) What code? b) I am not sure if this “on request” is acceptable for TC.
In summary, unless the authors make substantial revisions and add further details (which may require resubmission of the manuscript), I cannot recommend the current manuscript for publication in the TC journal.