Skip to Main content Skip to Navigation
Theses

Processus de dissolution des aérosols atmosphériques au sein des gouttes d'eau nuageuses

Abstract : Clouds affect both climate via the role they play in the Earth's radiation balance and tropospheric chemistry since they are efficient reaction media for chemical transformation of soluble species. Cloud droplets are formed in the atmosphere by condensation of water vapour onto aerosol particles, the cloud condensation nuclei (CCN). The water soluble fraction of these CCN governs the cloud microphysic, which is the paramount factor playing on the radiative properties of clouds. Moreover, this soluble fraction is the source of species imply in the oxidation/reduction reactions in the aqueous phase. Thus, it is of particular importance to understand the process controlling the solubilisation of aerosols in the cloud droplets. The main purpose of this work is to investigate experimentally and theoretically the dissolution of particles incorporated in the aqueous phase. From the studies conducted up to now, we have identify several factors playing on the dissolution reaction of aerosols. However, the quantification of the effects of these factors is difficult since the current means of study are not adapted to the complexity of cloud systems. First, this work consisted to perform a experimental system, compound by an open flow reactor, enabling to follow the kinetic of dissolution in conditions representative of cloud. This experimental device is used to a systematic characterisation of the known factors playing on the dissolution, i.e. pH, aerosol nature, aerosol weathering... and also for the identification and the quantification of the effects of other factors: ionic strength, acid nature, clouds processes. These experiments gave quantitative results, which are used to elaborate a simple model of aerosol dissolution in the aqueous phase. This model considers the main factors playing on the dissolution and results in a general mechanism of aerosol dissolution extrapolated to the cloud droplets.
Complete list of metadatas

Cited literature [183 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00005175
Contributor : Karine Desboeufs <>
Submitted on : Monday, March 1, 2004 - 2:03:12 PM
Last modification on : Friday, April 10, 2020 - 5:09:31 PM
Long-term archiving on: : Friday, April 2, 2010 - 8:58:55 PM

Identifiers

  • HAL Id : tel-00005175, version 1

Citation

Karine Desboeufs. Processus de dissolution des aérosols atmosphériques au sein des gouttes d'eau nuageuses. Géochimie. Université Paris-Diderot - Paris VII, 2001. Français. ⟨tel-00005175⟩

Share

Metrics

Record views

603

Files downloads

887