Summary

The authors present calculations to quantify the impact that thunder may have on atmospheric particles. One mechanism closer to the shock front acts to increase particle number and reduce size, and another coagulation mechanism further from the lightning channel has the opposite effect.

These calculations show very interesting and potentially important findings in an area with little research. This reviewer agrees with the conclusions that this area may yield unquantified feedback in various wider areas, such as modelling of cloud electrification processes and secondary ice formation. No faults or logical inconsistencies can be identified, and it is this reviewer’s opinion that this manuscript be published with very minor changes.

In a note to the authors for future work, it may be worth estimating sound pressure levels from US NLDN data of peak lightning currents. Anecdotally, there are also indirect measurements from electric field changes of some negative lightning discharges, for example in Africa, with mega amp currents (personal communication with Phil Krider). These would translate to sound pressure levels of near 200 dB (energy E=I²RΔt assuming R=2 Ω and Δt = 50 μs, peak overpressure P=sqrt(2ρc²⋅E_acoustic​) assuming E_acoustic is 0.01E, L_p​=20⋅log​(p/p₀​)).

Minor comments

• Line 99–100: It’s unclear where the We values stated derive from for droplets, ice crystals, etc.
• Lines 123 and 292: It’s unclear why Al₂O₃ and ice crystals must have 3 times the diameter of a water droplet to break up, if this could be explained further in this sentence.
• Few spelling mistakes where “extent” is misspelled “extend”: lines 134, 276, 298

Please see pdf file