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RESEARCH PRODUCT
Humidity effects on gravitational settling and Brownian diffusion of atmospheric aerosol particles
Gottfried Hänelsubject
Materials scienceThermodynamic equilibriumDiffusionThermodynamicsHumidityrespiratory systemAtmospheric sciencescomplex mixturesAerosolGeophysicsDeposition (aerosol physics)SettlingGeochemistry and PetrologyParticleRelative humidityPhysics::Atmospheric and Oceanic Physicsdescription
The dependency on relative humidity of the settling velocity of aerosol particles in stagnant air and of the diffusion coefficient due to Brownian motion of aerosol particles was computed for six aerosol types and different particles sizes in dry state. The computations are based (1) on mean bulk densities of dry aerosol particles obtained from measurements or from the knowledge of the chemical composition of the particles, (2) on micro-balance measurements of the water uptake per unit mass of dry aerosol substance versus water activity at thermodynamic equilibrium, and (3) on measurements of the equilibrium water activity of aqueous sea salt solutions. The results show a significant dependence of the settling velocity and Brownian diffusion of aerosol particles on relative humidity and on the particle's chemical composition.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1977-01-01 | Pure and Applied Geophysics PAGEOPH |