|The manuscript has improved significantly with the modifications and additions by the author. Nevertheless, some unclarities remain, which I am pointing out below. In addition, I am listing a few minor things and oversights. With Fig. numbers, Sect.s, and Lines I am referring to amt-2022-62-ATC2.|
A) The heating design is still unclear.
1) I appreciate the clarification about the structure of the heated-glass DS. This is what the author seems to call sandwich-like structure. I had confused that with the “double window” consisting of DS and at 13mm distance a second glass sheet with heated air in between, not being aware of that the DS itself has two glass layers with a heating layer in between. The detail that is provided in Fig. 8, could be included as text in Sect 2.5. Fig. 8 is not needed and should be removed.
2) The sentence referring to Fig. 8 in Lines 245/6 is still confusing or misleading due to a seemingly wrong use of “almost”. I would suggest to rephrase it to something like:
“The cooling rate is at most only about 50% of the heating rate. The cooling is passive by heat transfer to the surrounding air.”
3) The new paragraph in L 250-253 is not needed. While it is true, the actual difference between cooling and heating rates depends, in addition to the mentioned heat transfer coefficients, on the heating power of the electrically heated DS glass.
4) Heater 1 is a thermostat-controlled heater. I would change, in Fig. 3, “GAS TERMOSTAT” to “THERMOSTAT”.
5) I am still unsure about Heater 2. Is it the electrically-heated DS glass? Or is it a heater working together with a pump blowing air between the DS glass and the second glass sheet 13mm below the DS. In the previous MS version it said “air is pumped…, filtered, heated and finally blown through the double window space…”. Or is it yet another heater? In this respect, the sentence in L 227-229 is unclear. Is it Heater 2 controlling the inside temperature to be above (warmer) than -40degC? What is controlling the DS temperature to not rise above (warmer) than -5degC (cannot be a heater, but the author refers to Heater 2)?
6) L. 235 “…Mylar… prevents overheating of the DS above -5degC”. I would change that to be more specific and correct (and connect to the next sentence): “…Mylar… prevents overheating (of the instrument) and allows keeping the DS below -5degC… . Additionally, in warm weather… ”.
B) The resolution of ICE-CAMERA is not given. From the pixel size of 7 um and a 1:1 lens I am assuming that 1 pixel corresponds to 7um (pixel resolution). The author mentions “a fine calibration” without specifying the result of it (confirm 7.0 um/px?). The sentence in L 157 says something vague about the potential resolution of the macro lens, but not of the actual optical resolution of ICE-CAMERA. What are the smallest details/features that can be seen on the images? I doubt that details of 7um size can be seen if one pixel is 7um.
C) L 274-292 Adhesion of ice on DS: I am a bit confused. It seems you show that particles at normal speeds below their settling speeds would adhere. I.e. if they settle at settling speed they may not adhere.
Is there a limit of wind speed of 5 m/s imposed (mentioned in L 643) that has to do with adhesion?
D) The total number of particles is 81800. Of these only 5500 have been manually classified. All other images have gone through CNN classification followed by manual verification/correction (as explained in L 525-532). That means that many of the around 8000 images (10%) used for testing and compiling the confusion matrices have already been classified by CNN. Does this introduce a bias (improving accuracy in the confusion matrices)?
E) L 610 suggests that many particles are rejected for statistical analysis. It would be interesting to know roughly how many and for what reasons. Major reason wind speed threshold? Or too small particles?
Other minor things:
L. 54: Consider specifying why “In Antarctica, their (MASCS) practical application is mainly limited to coastal areas.”
The titles of Sect.s 2, 3, 4, and 6 are missing. Additionally, in the numbering Sect 5 is missing completely and Sect.s 6 appear twice.
L 158: “A 90 deg bending aluminium mirror…” seems to refer to the “45deg mirror mentioned earlier, I suggest again to use same terminology and names as before: “The 45deg mirror…”.
Now “DS” is not introduced when this term is first used in Sect 2.1. In addition, in some of the added text there appears “SD” instead of “DS” (L.s 126, 221, 262, 289, 337, 624).
L 211: 3.5 l/m => 3.5 l min-1 or 3.5 l min-1
L 261 galss => glass
L 271: “The non-contact…” => “A non-contact…” (talking about something not mentioned before)
L 297: “The adverse effect is an accelerated…” => “An adverse effect is, however, an accelerated…” (or “A disadvantage…”)
In Sect 4.1.4, “1)” is missing in the numbering.
In Sect. 4.1.4 4): Unclear how overlapping particles can be counted twice. Contrarily, two overlapping particles would be counted only as one (cluster). Similarly, merging close-by-particles (point 5) due to region growing results in less counts.
L 560: remaining 80% of the training => remaining 80% for the training
L 605: 8% regular plates => 9% hex. plates
L 611: “errors in … contributed to...” => “problems with … resulted in…”
Sentence in L 624/5 suggests that (it is clear that) sublimation on DS is less important than natural variation. This is not clear or obvious to me. Perhaps give a hint why or how. Similar in L 632/3.
L 631 HR => RH