Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride

<p>In this study, we analyzed the particle characteristics and cloud droplet growth properties of NaCl and CaCl<span class="inline-formula"><sub>2</sub></span>, which are powder-type hygroscopic materials applied in cloud seeding experiments, using the Korea C...

Full description

Saved in:
Bibliographic Details
Main Authors: B.-Y. Kim, M. Belorid, J. W. Cha, Y. Kim, S. Kim
Format: Article
Language:English
Published: Copernicus Publications 2025-08-01
Series:Atmospheric Measurement Techniques
Online Access:https://amt.copernicus.org/articles/18/3781/2025/amt-18-3781-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849235869718806528
author B.-Y. Kim
M. Belorid
J. W. Cha
Y. Kim
S. Kim
author_facet B.-Y. Kim
M. Belorid
J. W. Cha
Y. Kim
S. Kim
author_sort B.-Y. Kim
collection DOAJ
description <p>In this study, we analyzed the particle characteristics and cloud droplet growth properties of NaCl and CaCl<span class="inline-formula"><sub>2</sub></span>, which are powder-type hygroscopic materials applied in cloud seeding experiments, using the Korea Cloud Physics Experimental Chamber (K-CPEC) facility at the Korea Meteorological Administration/National Institute of Meteorological Sciences (KMA/NIMS) in South Korea. The aerosol chamber (volume 28.3 m<span class="inline-formula"><sup>3</sup></span>) enabled the observation of particle characteristics in an extremely dry environment (relative humidity (RH) <span class="inline-formula">&lt;</span> 1 %) that was clean enough to ignore the influence of background aerosols. The cloud chamber featured a double-structure design, with an outer (130 m<span class="inline-formula"><sup>3</sup></span>) and inner (22.4 m<span class="inline-formula"><sup>3</sup></span>) chamber. The inner chamber allowed the precise control of air pressure (1013.25–30 hPa) and wall temperature (<span class="inline-formula">−</span>70–60 °C), facilitating cloud droplet growth through quasi-adiabatic expansion. In this study, a cloud chamber experiment was conducted to simulate both wet adiabatic and stable environmental lapse rate conditions. The experiments were initiated at low RH (<span class="inline-formula">&lt;</span> 60 %), and the variations in the cloud droplet concentration and diameter were observed as RH increased, leading to supersaturation (RH <span class="inline-formula">&gt;</span> 100 %) and subsequent cloud droplet formation. NaCl and CaCl<span class="inline-formula"><sub>2</sub></span> powders showed distinct particle growth behaviors owing to the differences in their deliquescence and hygroscopicity. The rate of cloud droplet formation in the NaCl powder experiments was slower than that for CaCl<span class="inline-formula"><sub>2</sub></span>; however, the mean and maximum droplet diameters were approximately 2–3 and 10–20 <span class="inline-formula">µ</span>m larger, respectively. The particle diameter, including aerosols and droplets, varied from 1 to 90 <span class="inline-formula">µ</span>m, and large cloud droplets (30–50 <span class="inline-formula">µ</span>m) that served as the basis for drizzle embryo formation were also observed. Our study provides valuable insights for the development of new seeding materials and advanced cloud seeding experiments.</p>
format Article
id doaj-art-bdd8b9684347459db78f42f3da68327b
institution Kabale University
issn 1867-1381
1867-8548
language English
publishDate 2025-08-01
publisher Copernicus Publications
record_format Article
series Atmospheric Measurement Techniques
spelling doaj-art-bdd8b9684347459db78f42f3da68327b2025-08-20T04:02:32ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482025-08-01183781379710.5194/amt-18-3781-2025Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chlorideB.-Y. Kim0M. Belorid1J. W. Cha2Y. Kim3S. Kim4Research Applications Department, National Institute of Meteorological Sciences, Seogwipo, Jeju 63568, Republic of KoreaResearch Applications Department, National Institute of Meteorological Sciences, Seogwipo, Jeju 63568, Republic of KoreaResearch Applications Department, National Institute of Meteorological Sciences, Seogwipo, Jeju 63568, Republic of KoreaResearch Applications Department, National Institute of Meteorological Sciences, Seogwipo, Jeju 63568, Republic of KoreaResearch Applications Department, National Institute of Meteorological Sciences, Seogwipo, Jeju 63568, Republic of Korea<p>In this study, we analyzed the particle characteristics and cloud droplet growth properties of NaCl and CaCl<span class="inline-formula"><sub>2</sub></span>, which are powder-type hygroscopic materials applied in cloud seeding experiments, using the Korea Cloud Physics Experimental Chamber (K-CPEC) facility at the Korea Meteorological Administration/National Institute of Meteorological Sciences (KMA/NIMS) in South Korea. The aerosol chamber (volume 28.3 m<span class="inline-formula"><sup>3</sup></span>) enabled the observation of particle characteristics in an extremely dry environment (relative humidity (RH) <span class="inline-formula">&lt;</span> 1 %) that was clean enough to ignore the influence of background aerosols. The cloud chamber featured a double-structure design, with an outer (130 m<span class="inline-formula"><sup>3</sup></span>) and inner (22.4 m<span class="inline-formula"><sup>3</sup></span>) chamber. The inner chamber allowed the precise control of air pressure (1013.25–30 hPa) and wall temperature (<span class="inline-formula">−</span>70–60 °C), facilitating cloud droplet growth through quasi-adiabatic expansion. In this study, a cloud chamber experiment was conducted to simulate both wet adiabatic and stable environmental lapse rate conditions. The experiments were initiated at low RH (<span class="inline-formula">&lt;</span> 60 %), and the variations in the cloud droplet concentration and diameter were observed as RH increased, leading to supersaturation (RH <span class="inline-formula">&gt;</span> 100 %) and subsequent cloud droplet formation. NaCl and CaCl<span class="inline-formula"><sub>2</sub></span> powders showed distinct particle growth behaviors owing to the differences in their deliquescence and hygroscopicity. The rate of cloud droplet formation in the NaCl powder experiments was slower than that for CaCl<span class="inline-formula"><sub>2</sub></span>; however, the mean and maximum droplet diameters were approximately 2–3 and 10–20 <span class="inline-formula">µ</span>m larger, respectively. The particle diameter, including aerosols and droplets, varied from 1 to 90 <span class="inline-formula">µ</span>m, and large cloud droplets (30–50 <span class="inline-formula">µ</span>m) that served as the basis for drizzle embryo formation were also observed. Our study provides valuable insights for the development of new seeding materials and advanced cloud seeding experiments.</p>https://amt.copernicus.org/articles/18/3781/2025/amt-18-3781-2025.pdf
spellingShingle B.-Y. Kim
M. Belorid
J. W. Cha
Y. Kim
S. Kim
Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride
Atmospheric Measurement Techniques
title Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride
title_full Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride
title_fullStr Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride
title_full_unstemmed Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride
title_short Analysis of hygroscopic cloud seeding materials using the Korea Cloud Physics Experimental Chamber (K-CPEC): a case study for powder-type sodium chloride and calcium chloride
title_sort analysis of hygroscopic cloud seeding materials using the korea cloud physics experimental chamber k cpec a case study for powder type sodium chloride and calcium chloride
url https://amt.copernicus.org/articles/18/3781/2025/amt-18-3781-2025.pdf
work_keys_str_mv AT bykim analysisofhygroscopiccloudseedingmaterialsusingthekoreacloudphysicsexperimentalchamberkcpecacasestudyforpowdertypesodiumchlorideandcalciumchloride
AT mbelorid analysisofhygroscopiccloudseedingmaterialsusingthekoreacloudphysicsexperimentalchamberkcpecacasestudyforpowdertypesodiumchlorideandcalciumchloride
AT jwcha analysisofhygroscopiccloudseedingmaterialsusingthekoreacloudphysicsexperimentalchamberkcpecacasestudyforpowdertypesodiumchlorideandcalciumchloride
AT ykim analysisofhygroscopiccloudseedingmaterialsusingthekoreacloudphysicsexperimentalchamberkcpecacasestudyforpowdertypesodiumchlorideandcalciumchloride
AT skim analysisofhygroscopiccloudseedingmaterialsusingthekoreacloudphysicsexperimentalchamberkcpecacasestudyforpowdertypesodiumchlorideandcalciumchloride