the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 13 Dec 2024
On the impact of thunder on cloud ice crystals and droplets
Abstract. Calculations are presented on the impact of thunder on cloud particles. The results show that the creation of a shockwave front near the lightning channel results in shattering of ice crystals, droplets, and dust aerosols, the former being a yet unidentified mechanism for secondary ice production in clouds. At low altitudes shattering is more efficient. At the distance where the shockwave front decays to audio wave, it can cause agglomeration of particles. The cloud particles’ characteristics appear not very suitable for extensive acoustic agglomeration if the Sound Pressure Level (SPL) is below 120 dB. Nevertheless, even for SPL<120 dB, some agglomeration will occur. Agglomeration will occur readily if SPL>135 dB at sound frequencies 10–200 Hz. Agglomeration efficiency increases with height. More agglomeration will occur in pyroclouds, due to their large particle number densities. These results show that the electrical environment in clouds has, through thunder, effects on the size distribution and number density of ice particles and droplets, will hence influence thundercloud radiative properties, and it may be a significant driver of secondary ice production. As global warming may influence the occurrence rate of lightning, the mechanisms discussed here may induce a climate feedback.
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Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
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Preprint
(1050 KB)
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(1050 KB) - Metadata XML
- BibTeX
- EndNote
- Final revised paper
Journal article(s) based on this preprint
Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2024-3314', Anonymous Referee #1, 03 Jan 2025
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⋅Eacoustic) assuming Eacoustic is 0.01E, Lp=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
Citation: https://doi.org/10.5194/egusphere-2024-3314-RC1 - AC1: 'Reply on RC1', Konstantinos Kourtidis, 20 Feb 2025
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RC2: 'Comment on egusphere-2024-3314', Anonymous Referee #2, 03 Jan 2025
- AC2: 'Reply on RC2', Konstantinos Kourtidis, 20 Feb 2025
Interactive discussion
Status: closed
-
RC1: 'Comment on egusphere-2024-3314', Anonymous Referee #1, 03 Jan 2025
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⋅Eacoustic) assuming Eacoustic is 0.01E, Lp=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
Citation: https://doi.org/10.5194/egusphere-2024-3314-RC1 - AC1: 'Reply on RC1', Konstantinos Kourtidis, 20 Feb 2025
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RC2: 'Comment on egusphere-2024-3314', Anonymous Referee #2, 03 Jan 2025
- AC2: 'Reply on RC2', Konstantinos Kourtidis, 20 Feb 2025
Peer review completion
Journal article(s) based on this preprint
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Konstantinos Kourtidis
Stavros Stathopoulos
Vassilis Amiridis
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(1050 KB) - Metadata XML