Review of “Boundary Layer Dynamics after Rain Fronts: High-Resolution Reconstruction and Model Validation using ground- and drone-based Measurements” by Moormann et al. 

This study aims to understand chemical and meteorological processes occurring in the boundary layer during summer rain events, by using a combination of drone-based measurements, ground-based observations, and ICON forecast model data. The aim of the work is novel and interesting, yet the structure and the methodology suffer from a number of drawbacks which limit the impact and the full potential of exploitation for the work. Below I report my major comments based on my revision of the paper. 

General comments 

The structure of the Introduction section is chaotic and messy. It starts from understanding atmospheric processes during different weather events, then begins to talk about fronts, then of models and measurements, then again of atmospheric dynamics, Monin-Obukhov theory, drone-based observations, fronts,... Therefore I suggest improving the logic of the Introduction removing multiple jumps from one topic to the other, and more clearly demonstrating the gaps present in the literature and the key research questions addressed in the current work.  

Although not directly described in the Abstract, the methodology seems to be based not only on the ICON model, but also on HySplit back-trajectories driven by 0.25° GFS analysis data for calculation of boundary layer height. The use of back-trajectories in such complex terrain and driven by such coarse resolution meteorology is substantially problematic, as it is extremely difficult for such a meteorological model to successfully catch the micrometeorological and mesoscale processes occurring in the study site. In addition, it is not clear why you need this estimation when you have ceilometer data and higher resolution models. Last but not least, it is not clear why you restrict the focus to 24 hour only trajectories. 

I tend to agree with the other reviewer highlighting the relevant number of figures in the Supplementary, which also seem to be rather fundamental as per their discussion in the manuscript (in addition, with an odd and not consequential numbering). Figures in the Supplementary Material can support the findings, but should not contain relevant information that is fundamental to the discussion of the results.  

Section 5 only contains a summary of the findings, while an inclusion of the conclusions, limitations and next steps or outlook could be rather beneficial for improving the impact of the work over the long time horizon.  

Specific comments 

 Lines 9-11: I doubt there is such a clear division between research in polluted area and at continental rural mid-latitude sites. In addition, this is for sure out of scope for the beginning of the abstract.  

Lines 20-22: What does this mean more in general for boundary layer dynamics? 

Lines 90-139: Given the high number of data sources, perhaps having a Table with all data sources and key information extracted, as well as resolution, ... could be helpful for the reader. 

Lines 150-152: this note is not in the appropriate location. 

Lines 158-160: Not clear what is the assumption if this is something you are observing in your results. Maybe it is a speculative result? 

Lines 163-167: The caption contains material that is rather for the main text. 

Lines 173-175: Rather, the high correlation indicates the presence of the same temporal pattern, which is quite obvious and expected, but does not demonstrate the existence of a cause-effect relationship. 

Line 222: Change “Contrary” to “Conversely” 

Lines 229-232 and lines 309-311: Suggest rephrasing this sentence to highlight the findings and the eventual agreement with previous studies. The current structure does not reflect what is original in the observations, while it highlights more the previous studies.  

Lines 262-264: This sentence needs to be rephrased as it is not clear. 

Line 275: What do you mean by “aspiration of air masses”? (this term is also used at line 232 and 87, but it is not very technical).