Antarctic Time-Variable Regional Gravity Field Model Derived from Satellite Line-of-Sight Gravity Differences and Spherical Cap Harmonic Analysis

Round 1

Reviewer 1 Report

The paper by Feizi et al. is nicely written, and I have basically only two meta-comments:

1/ why did you use a spherical cap analysis? In many fields, people are using EOF (Empirical Orthogonal functions), that can fit any boundary shape. Oceanographers are using linear combination of Sheprical harmonics over oceans for example. Please explain your choice. Why not a set of EOF tailored to the coast of the Antartic?

2/ The choice of the regularisation of the inverse problem is not sufficiently discussed (eq. 19). I refer to the following paper:

https://doi.org/10.1016/0019-1035(92)90183-8

for an in-depth discussion of the regularisation process for line-of-sight gravity

Please see the attached handwritten notes for more comments

Comments for author File: Comments.pdf

English is almost fine.

 

 

Author Response

we would like to thank the reviewers for providing feedback and helping us improve our paper.  The answer to reviewer 1 is attached as a PDF.

Author Response File: Author Response.pdf

Reviewer 2 Report

See the attachment.

Comments for author File: Comments.pdf

See the attachment.

Author Response

we would like to thank the reviewers for providing feedback and helping us improve our paper.  The answer to reviewer 2 is attached as a PDF.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I have two more major comments.

Fig. 10 is suspicious if no filter is applied to the L2 JPL model. First, where is the north-south striping noise? Second, there should not be so much loss of signal in the L2 product. The authors may need to recheck their data source. Instead, I feel the SHA and L2 results should be very similar.

The authors claimed that Kmax=30 is the best as it is close to the ‘standard resolution of GFO’ (also because the yellow strips in larger Kmax scenarios). But the ‘standard resolution’ is neither a precise number nor widely accepted. The choice of Kmax seems to be arbitrary to make the results ‘look good’. I would suggest using other high-resolution product, like laser altimetry, to verify the details here.

Using ‘mGal’ or ‘muGal’, rather ‘m/s2’ in the manuscript.

Author Response

Dear Reviewer
I would like to thank you  for their insightful comments which make the paper more interesting and informative. Below please find our point to point responses to the reviewer's comments. The revised of version of the manuscript along with the highlighted modifications are also appended.
Sincerely Yours
Corresponding Author

Author Response File: Author Response.pdf