Please see attached file for comments.  Great job by the authors!

General

This paper describes a comprehensive data set obtained in the Arctic boundary layer over northern Greenland during a campaign in March/April 2024. There, a tethered balloon was used which was equipped with instrumentation for standard meteorological parameters but also with radiation and turbulence sensors. The authors state that the data are useful to characterize the atmospheric boundary layer (ABL) evolution especially with respect to transition events e.g. from cloudy to cloud-free conditions and for future comparison with model applications. An overview of the data is given and some events are described in more detail. 

I think that this unique data set can be very useful in future investigation of small scale boundary layer processes aiming e.g. to a better understanding of the ABL energy budget.  The paper is well organized and in general well written with clear logic. I propose some minor revisions (mostly concerning wording).    

Revisions

Equation 1: This formula assumes the constant temperature gradient of the standard atmosphere. However, the observed T-gradients were different. The temperature as a function of pressure is known with high vertical resolution from the measurements. So, one could take the average temperature between two pressure layers and calculate then z layer by layer?  (See e.g. equation 6.13 in the textbook of Pichler, 1986). This would improve the accuracy for z.

Line 11: better: one possible major …

Lines 14-15:  meaning of  ‘temperature rate’ is unclear here. Is it the change of temperature with time or the vertical gradient or something else?

Lines 27-28: I think, much older and thus original references need to be given here.

Caption Fig. 1: better ‘domain’ instead of ‘extent’

                        Replace ‘dots illustrate’ by ‘orange dots illustrate’ since there are also other ones.

Caption Fig. 3:   better: … probes distributed along the rope (not robe, that’s something else). Aren’t clouds often also within the inversion?

Table 2: why is turbulence data often unavailable?

Line 141: probably, the authors mean the maximum height of all balloon flights reaching more than 200 m height?

Line 143: better: During the first 11 RFs …. maximum heights reached by the balloon were mostly slightly below 500 m while ….. 

Line 144: better again ‘maximum’ profile heights’

Lines 181-182: In general, a wind speed above 20 m/s is not unrealistic in the Arctic. So, one could add that during the campaign wind speed was in general low, so that values above 20 m/s were considered as unrealistic and thus excluded.

Fig. 5:   what is called constant altitude is obviously not really constant. See green peak around 13:50. Another point: What is the reason for the green color dots near the red peaks?

And ‘near-ground’ is not always the same layer. E.g. during descents ´near-ground’ differs in the descent from ‘near-ground’ during ascent.

Caption Fig 7: at least on my screen the raw spectrum appears to be light green rather than blue and I do not see any orange color in the figure.

Caption Fig. 8: formulation needs improvement. You mean ‘Near-surface frequency of net infrared irradiances (Fnet) based on data around 30 m height’ ?

Line 238: better: 'were'  published or ‘will be’ published ?

Line 252/253: The sentence is somewhat misleading. The authors mean probably: Marine air masses reaching STN are influenced by their traversal over the (partly) sea-ice-covered ocean?

Line 253: delete likely, the surface always influences an air mass. Or is there a reason for decoupling here?  

Line 254: ‘…. Can frequently influence …. also this sentence part needs reformulation. The synoptic condition cannot be a prerequisite for the data. Do the authors simply mean: The synoptic situation at STN is furthermore influenced often by katabatic flows ..... ?

Line 277: replace ‘fields’ by ‘speeds’ (a wind field cannot decrease or increase).

Lines 280 – 281: A similar figure as Fig 11b and c for the observations (with the same vertical axes) would be helpful.

Line 283: The ‘thermal’ stratification

Caption Fig 12: sentence part starting with ‘color-coded’: please write complete sentence.

Line 292: ‘spatio’ means here in vertical direction? Or was the spatial variability (horizontally) derived from the reanalyses?

Line 310 and text below: the authors mean probably just the divergence of radiative fluxes (not the divergence of the radiation budget). Only changes in radiation are addressed, but  what about turbulence and phase changes? Changing wind speed will generate less or more mixing and as a consequence stronger or weaker stability.

Line 331: this formulation needs improvement. E.g.:   ‘ ... the arctic ABL due to their strong impact on vertical entrainment ‘.

Line 335: I suggest deleting ‘… all measurements from RTF12 are compared here’ and continue previous sentence part with …specific humidity together with the corresponding CARRA ....

The reason for this change is that the comparison is made in the paragraph starting in line 341 while the previous paragraph explains BELUGA measurements only. 

Reference

Pichler (1986) Dynamik der Atmosphäre BI Wissenschaftsverlag