Mapping and Assessing Variability in the Antarctic Marginal Ice Zone, the Pack Ice and Coastal Polynyas in two Sea Ice Algorithms with implications on Breeding Success of Snow Petrels - Revision 1
by Stroeve, J. C., et al.
This is revision #1 of the original manusript. The authors have improved the manuscript substantially and I appreciate that many of the reviewers' comments have been taken seriously and discussed properly. Thank you!
The paper is ready to go - pending a few minor edits which I list below but which do not require further attention from my side.
L103-L105: I agree that the katabatic winds are responsible for generation of coastal polynyas and for keeping them open by more or less constantly advecting the new ice formed to the leeward side of the polynya. However, I am wondering how far away from the coast the sea ice still "feels" the impact of the katabatic winds which I would expect to loose their influence within a few 10 kilometers from the coast with the synoptic winds taking over. I am wondering what the authors' reflection on this is and whether this sentence isn't perhaps misleading a bit.
L122: The authors stated in their rebuttal letter that they could not find the TC reference for Ivanova et al. 2015. Here it is: Ivanova, N., Pedersen, L. T., Tonboe, R. T., Kern, S., Heygster, G., Lavergne, T., Sorensen, A., Saldo, R., Dybkjaer, G., Brucker, L., and Shokr, M.: Satellite passive microwave measurements of sea ice concentration: an optimal algorithm and challenges, The Cryosphere, 9, 1797-1817, doi:10.5194/tc-9-1797-2015, 2015.
L149-161: I see that the authors have kept their definition of the MIZ. While I am fine with that, because a change of this definition would have meant to redo the study, I would have hoped to see two notes: i) waves often penetrate well beyond the 80% sea-ice concentration isoline (they break of consolidated sea ice). ii) the sea-ice type along most of the Antarctic sea-ice cover is pancake ice which differs from the Arctic.
I did not find a notion about how to define the sea-ice concentration threshold to delineate polynyas in Strong and Rigor (2013). Therefore I feel that the authors also could have underlined the choice of SIC < 0.80 for defining the ice class "potential coastal polynya" with a reference as suggested in my previous review (e.g. Massom et al. 1998, Annals of Glaciology, 27, 420-426)
L203-211: The authors are using data on the NSIDC polar-stereographic grid which is not a true-area grid. How did the authors compute the grid-cell area? Did they take the readily available grid-cell area data files from NSIDC? I suggest to mention this in the manuscript. A reader taking your manuscript as a model to carry out a similar study might not want to run into biased ice-category extent estimates because of the latitude-dependent variation of the grid-cell area of the grid used.
L362/363: Please check sentence: "... switch to positive in the while remaining ..."
L375: "... as a function longitude ..." I guess an "of" is missing here.
L392: I suggest to also write "Bellingshausen / Amundsen Sea" here, instead of "B/A Sea". The same applies to L625.
I have one minor general editoral comment: The authors could check usage of a capital "S" in seas when they refer to two regions such as "Ross and Weddell Seas". Currently, this is written in an inconsistent way, sometimes with small "s", sometimes with capital "S".