Arctic Stratosphere Dynamical Processes in the Winter 2021–2022

Round 1

Reviewer 1 Report

Please see my comments in the attached file.

Comments for author File: Comments.pdf

Author Response

Reply to Reviewer 1 is attached below

Author Response File: Author Response.docx

Reviewer 2 Report

The article presents an thorough analysis of dynamical processes in the winter stratosphere of 2021-2022. This is a really interesting information. The article can be accepted after a minor revision due to the following minor and presentation-quality comments:

Minor comments

1) Page 1, line 21: "The first minor SSW was limited by upper polar stratosphere whereas second one propagated to the middle and lower stratosphere". This aspect is not commented in the article, I suggest to add a few words on it in section 3.1 or 3.4.

2) Figure 3g, what is GHGS? The information from section 2 and figure caption does not completely explain what quantity is plotted and what is it units.

3) Page 13, line 368. Why do you compare Vpsc with winters of 2020 and 2011?

4) Page 14, line 388 and also Section 2. A few more comments on the final SW definition will be appreciated by tof he general reader. The given information in the present form raise many questions like "Is final SW the same as SSW, but without vortex restoration?", "How can final SW be earlier (4 March) than major SSW (20 March)".

5) Figure 7. Is the trends shown (and correlation coefficients cited) statistically significant?

6) Page 15, line 406. "This double structure of the zonal mean wind is favorable for reflecting wave activity downwards, ...". Is this an empirical observation or a proved fact? Is there any references explaining/proving this dependence?

Presentation quality comments:

1) Page 2, line 53 : "...on which particles...". I suggest reformulating this sentence

2) Figure 2b is of strikingly low quality

3) Figure 3 caption - missing letter (e), (g) is used twice instead

4) Page 14, line 379 - the word "dates" repeated twice

5) Page 16, line 442, "increase" or "decrease"?

Author Response

Reply to Reviewer 2 is attached below

Author Response File: Author Response.docx

Reviewer 3 Report

Vargin et al discuss the winter of 2021/22 and the behaviour of the stratosphere. The paper is a description of events and background drivers to this winter. It discusses the evolution of the atmospheric circulation and polar stratospheric cloud amounts. It does not add major new results to the literature but seems like a valid topic to document the event. I have a few mainly minor suggestions and some requests for better justification of the conclusions, for example about wave reflection which are very speculative:

The introductory referencing misses some key papers. For example the paper by Rex et al, Geoph. Res. Lett. 2006 has documented the dramatic increase in cases of extreme cold stratospheric winters conducive to ozone depletion in the northern hemisphere.

Abstract L22: ...was limited to the upper polar....whereas the second....

L26: this is warming not heating as the temperature change is adiabatic

L44: on average

L48: Holton and Mass, J.A.S., 1976 showed these internal SSW events for a simple 1D model and Scaife and James, Q.J.Roy.Met.Soc., 2000 generalised it to a 3D stratosphere only primitive equation model.

L88: There is evidence that this particular winter anomaly was also due to the extreme Indion Ocean Dipole: Hardiman et al, Atm. Sci. Lett., 2000.

L124-131: This is a rather unusual definition of vortex breakup  according to my understanding. Why not just use U<0 with no prolonged subsequent return to westerlies? The 31d smoothing also seems like a long timescale. What happens if this is removed and just U<0 is used? does it affect conclusions?

L142: Andrews and McIntyre, J. Atm. Sci., 1976 is the correct reference for TEM diagnostics and formulation.

Figures: please remove the surrounding boxes from panels

L257: ...in late February....accompanied by....

Some figures have too many multiple panels, e.g. Fig.3 please reduce unnecessary panels.

L408-410: this argument about the double jst structure is rather speculative and unconvincing. Can you show that the wave tilt with height became vertically oriented at this time? this would be consistent with reflection as in the references about internal SSW events above...

L457: there is no such thing as adiabatic heating, only adiabatic warming

Fig.9 what level is this?

L492: this statement is too strong and it would be better to say "not fully understood"

L498: There is a review paper by Scaife et al ACP 2022 which would be a good reference for seasonal forecast skill involving the stratosphere.

L512: rather than positive SST per se, is this more likely simply due to the higher than normal pressure in the N Atlantic during La Nina? Similarly, the drop in wave activity at L513, 536, 537 is consistent with the occurence of La Nina. See for example Bell et al., J. Clim., 2009, Taguchi and Hartman, J.Clim., 2006

L532: cooling (warming)

Author Response

Reply to Reviewer 3 is attached below

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have considered my comments seriously. I feel the paper has improved compared to the previous version. Please also use a native proofreader to ensure there are no misspells or grammatical errors in the paper. Other than that, the paper can be accepted.