Reconciling atmospheric water uptake by hydrate forming salts.
Environ Sci Process Impacts
; 22(8): 1759-1767, 2020 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-32697206
Magnesium and calcium chloride salts contribute to the global atmospheric aerosol burden via emission of sea spray and mineral dust. Their influence on aerosol hygroscopicity and cloud forming potential is important but uncertain with ambiguities between results reported in the literature. To address this, we have conducted measurements of the hygroscopic growth and critical supersaturation of dried, size selected nano-particles made from aqueous solution droplets of MgCl2 and CaCl2, respectively, and compare experimentally derived values with results from state-of-the-art thermodynamic modelling. It is characteristic of both MgCl2 and CaCl2 salts that they bind water in the form of hydrates under a range of ambient conditions. We discuss how hydrate formation affects the particles' water uptake and provide an expression for hydrate correction factors needed in calculations of hygroscopic growth factors, critical super-saturations, and derived κ values of particles containing hydrate forming salts. We demonstrate the importance of accounting for hydrate forming salts when predicting hygroscopic properties of sea spray aerosol.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Sales (Química)
/
Agua
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Environ Sci Process Impacts
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Reino Unido