I think the paper is well written, mostly and has some important results. 

My suggestions are that

(1) the introduction could be more succinct and some of the literature in a separate literature synthesis section

(2) the Takahashi breakup scheme is applied for unrimed ice particles. I think this needs to be caveated because the paper suggested it was the rimed particles - as did Vardiman (1978)

(3) It should be more clear where teh rimed fraction of ice crystals comes from - how this is extracted from the observations. 

(4) there has been another study on mode 2, which is referred to. So the sentence about Latham and Warwicker being the only study should be revised. 

See attached PDF

Review of manuscript "Secondary ice production processes in wintertime alpine mixed-phase clouds" by Georgakaki et al. 

Overall the paper is well written and presents important aspects of various secondary ice productions mechanisms in orographic mixed-phase clouds.

I recommend the publication of the paper in ACP after addressing the minor issues enlisted below.

1. Line 211: Please clarify if the whole 2D-S spectrum was considered for estimating the observed ice number concentrations. It is good practice to remove particles smaller than 200 um while reporting the number concentration of ice particles from the 2DS probe as the shattering removal algorithm may not remove all the artifacts. Authors can add a few lines on these uncertainties. 

2. Line 258: Define ERA5

3. Line 261: Define MODIS