The authors address the referee comments.

For the paper to be ready for ACP, the authors should address the following comments:

P. 1

L. 17: I suggest “contrary” instead of “contrarily”. See also P. 16, L. 3, P.17, L. 31.
L. 20: Perhaps mention the four time periods.

P. 2

L. 3: I suggest “Northern Hemisphere” throughout the paper. Similarly, “Southern Hemisphere”. See P. 12, L. 32.
L. 21: Perhaps write: “…due to the quality of the temperature observations not being sufficiently high…”. This explicitly states that the quality is not high (I find your statement a bit vague.).
L. 26: Editorial point: I suggest you do not start a sentence with a chemical formula. You could write: “The SF6…”.
L. 33: I suggest you provide a reference for the concept of reanalysis. Examples could be: Bengtsson and Shukla, 1988; Trenberth and Olson, 1988.

P. 4

L. 28: Is there a limit on the size of the overshoots/undershoots allowed?
L. 33: Maybe this is my problem, but I have difficulty understanding the sentence defining the mean of the spectrum, AoA. Maybe this is not important, but where does the mixing ratio reach the same value as the source region? Could you explain this more clearly?

P. 6

L. 2: To be more objective, I suggest: “The XXX offline transport model…”.
L. 15: Check that you have introduced the ECMWF acronym. Please ensure that you introduce all acronyms, both in the abstract and main manuscript. Another example is TOMCAT (L. 28).
L. 31: CTMs.

P. 7

L. 18: I suggest you do not start a sentence with an acronym. Consider this elsewhere in the text, including acknowledgments and use of code.
L. 26: Do you need “quite”?

P. 8

L. 13: Identify explicitly if the minimum is at 6S.
L. 17: I suggest for numbers less than or equal to ten you use the word version, i.e., “seven” here and elsewhere (e.g., P. 8, L. 32). Explain in more detail why the result is remarkable, or omit the subjective description.
L. 21-22: I suggest you quantify these “significant” differences.

P. 9

L. 3: “apparently” is vague. Unless you can justify its use, I suggest you remove this word. Same for P. 9, L.20, and P.9, L. 28. And elsewhere in the text.
L. 4: “joins” reads oddly. I suggest: “…agrees with their…”.

P.10

L. 4: “…tropopause, and are…”.
L. 6:Do you need “rather”?
L. 14: In what sense is this trend significant? Larger than the random variability? This will help understand comments regarding significance later in the paragraph.
L. 17: You write “modelled” here whereas elsewhere you write “modeled”. Please be consistent in your use of UK or US spelling.

P. 11

L. 25: Perhaps provide more explanation on why you use these different periods. Do you compare the results for robustness?

P. 12

L. 15: “Figure 10…”.
L. 19: Why is this unexpected? Unless you can explain the use of this subjective term, omit it.
L. 21: I suggest: delicate -> difficult.

P. 13

L. 4: Fig. -> Figs.

P. 14

L. 1: “…2 (…”.
L. 6: Is “exactly”, a strong qualifier, a correct description here?
L. 11: Why is this result striking? Unless you can explain the use of this subjective term, I suggest you limit yourself to an objective description.
L. 16: Identify the intercomparison.
L. 17: CCMs.
L. 16-21: I suggest you quantify the trends mentioned.
L. 25: Why is this surprising? Unless you can justify the use of this subjective term, limit the discussion to objective matters.

P. 15

L. 25: 1990s. And elsewhere (same for 1970s).
L. 26: Why is this interesting? Unless you can justify the use of this subjective term, limit the discussion to objective matters.
L. 34: probably-> likely.

P. 16

L. 5: Here you have “parameterization”, elsewhere “parametrization”. Please be consistent. I would suggest you use “parametrization”. Is “believe” appropriate here? Perhaps use “understand”.
L. 12: I suggest the form: “… (i.e., …”. Same elsewhere.
L. 16: “…of the residual…”.
L. 32: “…do not seem…” sounds vague. Perhaps write “… are not supported…”.

P.17

L. 16-27: I suggest you quantify the trends discussed in this paragraph.

P. 27

Fig. 2 caption: I suggest that you indicate the meaning of the end-points of the colour scale, e.g., red/blue relatively high/low values. I suggest you do the same for other similar figures.

P. 31

Fig. 6: I suggest you make the thick lines a bit thicker to make them stand out more clearly. Consider for other similar figures.

P. 33

Fig. 8: Identify the two legends in the caption.

P. 35

Fig. 10 caption: Identify the units of the plot. Same for other figures.