The present manuscript deals with the calibration of the 1064 nm channel of CALIPSO. The calibration of the 1064 nm signal is done via the 532 nm signal. However, some corrections are necessary due to wavelength dependent signal attenuation in the stratosphere above the cirrus clouds. It once more shows the great care and effort by the CALIPSO team to provide the best possible data set from the CALIPSO mission. The scientific world can learn from their great expertise to solve the challenges of spaceborne lidar observations. The manuscript is clearly written and just needs minor revisions before publication.

Major comments:

1. What is the highest ratio of the two-way transmissions recorded with SAGE-II and SAGE-III? Your color scale ends at 1.05, but maybe in extreme events higher ratios are possible, e.g., in the case of Pinatubo. Could you also check ground-based lidar or AERONET observations of the AOD at these wavelengths in the stratosphere, if they provide higher values for some events? I agree, that higher ratios are not that common to be considered for the global observations of CALIPSO, but might occur.
2. Smoke layers lingering around the tropopause might not be included in the stratospheric AOD. However, it was often observed that cirrus clouds form in these smoke layers. Recent studies using fluorescence lidars make these layers more visible, e.g., Gast et al., 2025 (and references therein).

Minor comments:

• A short outline of the article at the end of the introduction is common.
• Generally, I would recommend to name the subfigures a, b, c … for all figures.
• You mention future space missions operating an elastic lidar at 1064 nm. Already now, the Chinese ACDL is in space and operates at 1064 nm. Unfortunately, the data are not yet publicly available.
• L179/180 Actually, under unperturbed conditions this ratio is everywhere around 1.0.
• L200: Actually, it is still debated whether a pyroCb event or self-lofting was responsible for the stratospheric smoke observed in Siberia.
• L219 Do I understand it correctly, that the described corrections will not be applied to the v5.0 data release, because the funding ends now?
• L225-232 In Chapter 4, you’re discussing the ratio of the two-way transmittance and from Chapter 5 onwards, you mostly speak about the calibration bias. A small sentence at the beginning of Chapter 5 would smooth the transition. Also, the true value of 1.02 mentioned in line 230 is just an assumed true value taken from the same location in Fig 5, which is actually for a different year and different month. I got a bit confused here and other readers might be as well.
• Fig 8 + 9: May I suggest to add the perturbated extinction coefficient and attenuated backscatter coefficient to figures (left and center).
• Fig 10: I am just wondering how a zero-layer scene would look like as I assume that a planetary boundary layer should be always present. However, this question is not directly related to the findings presented in your study.
• L367 The value of 1.05 is referred to the upper end of Fig 5+6, which display some months of the years of 2019 and 2020. Is it also the upper end of Fig 1+4 which report the SAGE-II and SAGE-III results? See also my major comment 1.

Technical Corrections:

• Fig 5+6 The scale of the color bars is quite small. I would suggest to plot just one color bar for all 4 subplots.
• Fig 11 The date in the caption is wrong. It should be 16 June.
• Fig 14 Again, the date in the figure caption is wrong. In the plots it is stated 2 January.
• Fig 15 In the caption you want to refer to Fig 14 not 15. Furthermore, the calibration coefficient was increased by 5% (or by a factor of 1.05) and not 1.05%.