Direct effect of aircraft soot emission: a laboratory view
Résumé
Direct effect of aviation on the atmosphere is related to the impact of aircraft soot emission on the contrail formation. A new laboratory approach is elaborated to obtain a more complete knowledge on the potential of aircraft-generated particulates to act as contrail nuclei. A comprehensive examination of the morphology, microstructure, and surface che1nistry of engine soot and its laboratory-made surrogate is performed using various experimental techniques. It is found that engine soot particles may be separated in two components: a main fraction and a fraction of impurities. The high concentration of soluble inorganics and organics stimulate a significant water uptake by soot particles at low temperatures. Possible pathways of the cloud condensation model (CCN) /ice nuclei (IN) formation in the plume are suggested. In the cooling plume, the hydrophilic fraction of impurities of aircraft generated soot would nucleate ice in the condensation-freezing mode, whereas the hydrophobic main fraction allows a direct ice deposition at low temperatures. Insoluble aerosols of the aircraft exhaust would increase the background level of ice nuclei in the upper troposphere (UT) causing the cirrus cloud formation.
Origine | Fichiers produits par l'(les) auteur(s) |
---|
Loading...