Dear authors,

Thanks for the revised manuscript. The referees either asked for a minor revision or marked that she/he is not willing to review the revised manuscript. This puts the burden of the remaining review on my shoulders. Anyhow, I find your changes in response to the reviews acceptable, besides some minor details discussed below.

On the other hand, the reports from the referees were quite short and my opinion is that they missed some problems. For this reason I feel forced to raise some additional points before I can accept the manuscript for publication. These issues deal presentation issues only. Here I can mention that in an ongoing study we try mimic DARDAR in some aspects and it has been far from straightforward to figure out what settings that actually are being used. I see some similar problems in this manuscript.

Main comments:

Just keeping track of which version that is discussed needs an alert brain. On page 3 it is declared that v2.1.1 will be denoted as v1, but still v2.2.1 is used in the text (e.g. page 7,line1) and it is also called the "old" (e.g. in text of Figure 1). In addition, it has already caused us confusion to call the "old" version v1 in the manuscript, when it has the official name v.2.1.1. Do you know the official version number of the "new" version? If it will v3.x, I strongly recommend to use call the old version v2 and the new v3. Anyhow, consider the naming and how the names are used in the text.

As a side note, the ATBD found at the ICARE site

http://www.icare.univ-lille1.fr//projects_data/dardar/docs/varcloud-algorithm_description-v1.0.pdf

has a name indicating that is valid for v1. Is it also valid for v2.1? I suggest to clarify this on the site.

I see a logic in have you organised Sections 2 and 3, but I think it causes problems. Take the mass-size relationship as example. It is introduced on page 5 and you have quite a bit of discussion here. You get back to the subject in the start of Sec 3.2, and have another relative long discussion. Here you introduce the "BEST" parameterisation, and as a reader you then think that this is the one that you have selected (as you call it BEST). But still no values given. The story is continued in Sec 3.2.3, and first here the final parameterisation is mentioned ("Composite"). And then you have to go to Table 1 to actually see the values selected. Note also that you define BFM on page 5, but you still go back and use citations here and there.

The story around x and y of Eq. 5 is shorter but the selected values are only reported as comments inside a figure. If you are looking for these values specifically, it will probably take a while before you locate the values. And here are the old values not reported at all, which should be given as well.

There are more similar examples, but I hope you get my point without listing those as well.

My suggestion is to clearly report all parameter values of concern in tables (both old and new ones, following the present Table 1), and refer to the tables already when the parameters are introduced in Sec 2. The reader can then easily find and compare old and new parameter values, without risk of confusion. How you selected the new values can still be discussed in Sec 3. I would also suggest to make Sec 2 as condensed as possible and to avoid discussing the same subject both in Sec 2 and 3.

I hesitate to suggest things that makes the manuscript longer, and even more hesitation to bring up my own work. So take the following lines only as a tentative suggestion, originating from my personal curiosity. DARDAR IWP has been used as broad reference for the treatment of ice in models and products. The most recent one is from us:

https://www.atmos-chem-phys.net/18/11205/2018/

It seems that the new version gives lower mean IWP. Possible to give a rough number?


Further comments:

The abstract needed to be changed, but has now become quite long. It can be shortened by removing less important comments, such as "collected during several campaigns performed between 2000 and 2007 in different regions of the globe".

In addition, the sentences "Larger IWC values are found with the new version in the cold regions detected by the lidar." and "The new lidar ratio values lead to a reduction of IWC at cold temperatures" seem to contradict.

Page 1, line1-3: For me the sentence does not make sense. Anyhow, I suggest to remove the sentence as it is not needed. The motivation should be known to readers of AMT.

Page 4, line 11: Another example where the information is spread out. As a reader you get the impression that a full representation of the S profile is included in the state vector, while below Eq. 10 it becomes clear that the state vector only contains a and b. More generally, the way you discuss the state vector also raises the question if the formulation of x has changed or not? If there is no change, why not refer to the article where x is best presented? That is, either skip the details, or clearly state initially that it is a recap (and keep all discussion of the content of x together).

Page 5, line 7: Is Z calculated for totally random orientation or horizontally aligned particles? (I have failed to find a clear statement of this in the DARDAR documentation, so would be good to get it clarified.)

Page 5, line 24: Not just "especially", it will not work without a priori.

Page 8, line 33: As far as I can see alpha and beta are not defined inside the manuscript. This is an important change and should be visible in a table. Also note the risk of confusion between this alpha and visible extinction.

Page 12, line 4: Don't understand "a small error was set on the a priori in the cost function". Do you mean that the a priori uncertainty applied is small?

Page 12, line7-14: This part took me a while to get. Consider a rewrite.

Page 13, line 1: "2" should be "two". This applies also to other places in the manuscript.

Page 17: Some error here. Most references are written in italic.

Figure 3b and 3c: Should it not be ln(N') and ln(N*0) on the x-axis.

Figure 4: should not the last reference be Heymsfield et al (2014).

Figure 9 and 10: Top row of panels are identical to Fig 8, so seems unnecessary to repeat these panels. And just good to make the figures smaller.

Thanks for your changes. The manuscript is approved if you just fix some small things I noted:

Page 1, line 11: Change "from 5%" to "with 5%" or "by 5%".

Page 4, line 5: Several sentences are here in italic.

Page 4, line 29: You cite Table 2 before Table 1. Make sure you cite tables and figures in the correct order.

Page 5, line 15: Missing space before (Brown ...