This article is appropriate to support the publication of this data set. I was able to download the data and plot samples. I felt the accompanying metadata files and the readme files did a nice job in explaining the dataset. I felt this submission was of high quality and I would trust the dataset as useful.

Review of ESSD manuscript

Quality-controlled meteorological datasets from SIGMA 2 automatic weather stations in northwest Greenland, 2012– 3 2020

by Nishimura and others

General

This paper presents approximately eight years of quality-controlled datasets of two automatic weather stations (AWS) on the ice in NW Greenland, one situated on the contiguous ice sheet and one on a detached coastal ice cap. This region is climatologically very interesting as well as rapidly changing, as described in numerous recent publications. These AWS data are highly valuable for process understanding, climate monitoring, and model evaluation/satellite validation, and deserve to be published. The data have been extensively quality controlled as described in this paper. The resulting dataset appears clean and robust and useful for users. My main problem is the non-concise and often unclear writing style in this paper, which makes the paper hard to digest and, more seriously, in places leads to confusion. Although it is a relatively minor remark, it will require a significant effort by the authors to remedy this.

Major comments

I would like to encourage the authors to critically go through the MS text again to improve the readability and accuracy of the text. The writing can be more concise and precise. Some examples (not exhaustive) are listed below as minor comments. And in the process please aim for a shorter paper.

Table 2 would be better placed at the very beginning or end of the text.

This paper presents an observational dataset, so it is more logical to start the introduction with the history and importance of in situ observations in Greenland.

Section 5 also discusses derived data, such as positive degree days, lapse rates but also average seasonal cycles, etc. Not sure such (admittedly basic) analysis has a place in a data journal.

Minor comments: 

l. 17: an -> the

l. 25: ""snow height degradation", unclear, do you mean snow height decrease or snow metamorphism?

l. 37: "however, the existing in situ meteorological data are insufficient for these purposes", unclear, do you mean that current observational coverage is insufficient? It is quite good in Greenland when compared to e.g., Antarctica.

l. 51: "analytical values of various numerical models", unclear, do you mean "output of numerical models"?

l. 54: please explain 'sensor noise' and 'natural factors'.

l. 56: please explain QC or better simply write out throughout.

l. 76: " It is considered" the fact that the surface consists of accumulating snow/firn proves that this is the accumulation area.

Fig. 1a: I suggest including the GC-Net stations as well.

l. 78: "is supposed to be", unclear, was it intended to be at the equilibrium line, or is it thought to be there?

l. 80: " The surface condition at this site varies (see Fig. 2), and surface melting has occurred in warm years". Obviously, surface melting occurs at the equilibrium line. Did you perhaps mean "net ablation"?

l. 97, Figure 2: mainmast -> main mast (also elsewhere in text).

Figure 2: why is date given only in lower plots?

l. 113: cyclone battery?

Table 1 caption typo: observaion -> observation

Table 1: accuracy of wind direction, unclear what is meant here.

Table 1: It appears that for the radiation measurement the sensitivity rather than the accuracy is listed?

l. 131: some, not all?

l. 133: "Because the vertical radiant flux against the inclined surface needed to accurately calculate the surface albedo and surface energy balance is affected by the sloping surface at the SIGMA-B site, we calculated the slope-corrected downward shortwave radiation (SWd_slope) from the corresponding observations using the correction method in Jonsell et al. (2003) and Hock and Holmgren (2005)." This sentence is unclear.

Table 2: in line 147, 'transmittance' is indicated by lowercase 't_r', in Table 2 we see an uppercase 'T_r' which is called 'transmissivity'. Are these the same things?

Section 4.1: I suggest listing all range values in Table 3 and not to repeat these in the text, to improve readability. Instead, for each correction it would be nice to mention the % data affected.

l. 214: I do not understand this correction: why giving a clearly wrong measurement an arbitrary physical value?

l. 224 and 236: 'electrical noise', what is this? Earlier you used 'sensor noise', is this the same?

l. 226: why can alfa_sw and alfa_nir not be lower than 0.95 and 0.90? Or do you mean 'higher'?

l. 232: Are these the conditions for which the data are flagged as erroneous? It seems to be the other way around.

l. 237-240: You give the data a physical value (zero), would it not be better to not do that unless for instance when SW_TOA < 0?

l. 249: the surface consists of snow or ice, so how can its temperature become positive?

l. 299: Six hours of calm weather is not impossible, why this arbitrary value? Why not use the wind speed at the other AWS to check this?

l. 355: Why is wet snow treated differently at both sites?

Figure 4, 6, 8: Consider reducing symbol size.

Review of "Quality-controlled meteorological datasets from SIGMA automatic weather stations in northwest Greenland, 2012-2020" by M. Nishimura et al. 

B. Vandecrux (bav@geus.dk)

The article describes the valuable meteorological data collected by two weather stations in northwest Greenland and the processing thereof. The article is clearly written, the key elements of the AWS systems are thoroughly described and the figures are of very good quality. I only have minor comments on the manuscript. It is great that this data is being published and distributed freely. Nevertheless I am concerned that many data users will wonder why there is only data up to 2020. Adding recent data will certainly increase reuse and citations. If this is not possible for some reason, then it should be stated clearly in the article. I am also strongly encouraging (and I think ESSD does as well) the publication of the scripts that are behind the data processing. This is key to making this dataset and article fully reproducible. After addressing these two points and the minor comments listed below, the article will be a great asset for ESSD.

Comments on the article:

- abstract: ESSD requires that the dataset DOI appears in the abstract. Please add the two DOIs of the two level 1.3 datasets.

- l.22: "snow height increased" by how much? The use of "snow height" is misleading in the accumulation area. In many studies, snow more than one year old is not refered to as snow anymore but firn, so l first misunderstood this statement as the "annual snowfall is increasing". If the author do not distinguish snow and firn, then the total snow (+firn) thickness, and thickness change, are actually not measured. I recommend changing to "surface height" or "snow surface height". For Sigma-B, it would be nice to state clearly if it is standing on bare glacial ice. In that case "snow height" can be used.

- l.24: "decrease" by how much? Again, for snow height, do you mean that the annual maximum snow height is decreasing or that the surface height is generally decreasing?

- l.26: "notable snow height degradation" Not clear why it is notable or with regards to which normal it is a degradation. Please rephrase.

- l.97: "mainmast" two words?

- l.123: "cm" line 104-105 you use m for instrument depth, now cm for height. Please be consistent. Potentially use only SI units.

- table 1: It should be stated whether RH is provided with regards to water or with regards to ice (in subfreezing conditions). Some sensors do the conversion automatically, some don't. If it is with regards to water, then a corrected RH could be provided accounting for the different saturation point in subfreezing conditions. Or at least potential correction methods should be listed.

- Section 3: I am missing a discussion of the sensors' known limitations, it could be either included under the AWS system description subsections or in a section of its own at the end of the manuscript. It should estimate how often those problems my occur and point at potential way to remidiate them. Some of these limitations are:

- RH sensor clogging up with rime (https://doi.org/10.1007/s10546-004-7955-y)

- Unventilated thermometer overheating in low wind and clear sky conditions.

- Radiation sensors and anemometers being shadowed/sheltered by the station mast (https://doi.org/10.1029/2010JD015507)

- l.218: if RH is given with regards to ice, then supersaturation is not uncommon on the ice sheet up to ~110% and this filter may be too strict. If RH is given with regards to water then values >100 are unlikely.

- l.226: "lower" higher?

- l.243: Please avoid this use of brackets in equations to indicate interchangeable variables. Brackets have a defined meaning in equations. Either spell out two equations or use a subscript "i" in the equation and define it in the text like: "i being either u or d" 

- Section 4.1.5: Do you use the same filters for "sensor_height" as for "sh"? It should be mentioned in the text.

- l.317: "weak electric pulse" where does that pulse come from, why is it weak and how does this relates to the radiation measurements?

- l.331: same comment as line 243

- l.409: since the snow temperature sensors' installation depths were given in meter, I misunderstood the "-1" as meter. Please be consistent with the units.

- l.445: please give mean annual PDD and its standard deviation to support this statement.

-l.454: Is there any net ablation years? Does the station allow to measure the ice ablation? Is there any measurement (e.g. stakes) of the ice ablation? Please elaborate on this.

- l.472: shouldn't the lapse rates be negative?

Comments on the data files:

- Commercial formats like Microsoft Word should be avoided. Please replace by a text file.

- The station coordinates (potentially through time?) and a table giving the meaning of each variable (as they are named in the data files) should be provided at least in the readme file, or even better: in separate, machine-readable files (e.g. csv, tsv).

- The date format used is non-standard. ESSD encourages ISO 8601 (or alike). Please specify if time stamp is local time or UTC.