Technical note: Sublimation of frozen CsCl solutions in an environmental scanning electron microscope (ESEM) - determining the number and size of salt particles relevant to sea salt aerosols

0571947 - ÚPT 2024 RIV DE eng J - Článek v odborném periodiku
Vetráková, Ľubica - Neděla, Vilém - Závacká, Kamila - Yang, X. - Heger, D.
Technical note: Sublimation of frozen CsCl solutions in an environmental scanning electron microscope (ESEM) - determining the number and size of salt particles relevant to sea salt aerosols.
Atmospheric Chemistry and Physics. Roč. 23, č. 7 (2023), s. 4463-4488. ISSN 1680-7316. E-ISSN 1680-7324
Grant CEP: GA ČR(CZ) GA22-25799S
Grant ostatní: AV ČR(CZ) StrategieAV21/23
Program: StrategieAV
Institucionální podpora: RVO:68081731
Klíčová slova: thermodynamics * ESEM * concentrated-solutions * lower troposphere * spray aerosol * ice * snow
Obor OECD: Climatic research
Impakt faktor: 6.3, rok: 2022
Způsob publikování: Open access
https://acp.copernicus.org/articles/23/4463/2023/

We present a novel technique that elucidates the mechanism of the formation of small aerosolizable salt particles from salty frozen samples. We demonstrated that CsCl may be a suitable probe for sea salts due to its similar subzero properties and sublimation outcomes: CsCl substantially increased the visibility of the salt both during and after ice sublimation. Hence, we identified the factors that, during the sublimation of a frozen salty solution, are important in generating fine salt particles as a possible source of salt aerosol. The number, size, and structure of the particles that remain after ice sublimation were investigated with respect to the concentration of the salt in the sample, the freezing method, and the sublimation temperature. The last-named aspect is evidently of primary importance for the preference of fine salt crystals over a large compact piece of salt, we showed that the formation of small salt particles is generally restricted if the brine is liquid during the ice sublimation, i.e. at temperatures higher than the eutectic temperature (Teu). Small salt particles that might be a source of atmospheric aerosols were formed predominantly at temperatures below Teu, and their structures strongly depended on the concentration of the salt. For example, the sublimation of those samples that exhibited a concentration of less than 0.05 M often produced small aerosolizable isolated particles that are readily able to be windblown. Conversely, the sublimation of 0.5 M samples led to the formation of relatively stable and largely interconnected salt structures. Our findings are in good agreement with other laboratory studies which have unsuccessfully sought salt aerosols from, for example, frost flowers at temperatures above Teu. This study offers an explanation of the previously unexplored behaviour.
Trvalý link: https://hdl.handle.net/11104/0344258


Vědecká data: Mendeley Data