TY - GEN

T1 - Vertical Aerosol Transport in the Middle Atmosphere

T2 - book chapter

AU - Beresnev, S. A.

AU - Gryazin, V. I.

AU - Kochneva, L. B.

PY - 2008

Y1 - 2008

N2 - This study continues the analysis of the determining forces responsible for vertical aerosol transport in the middle atmosphere (upper troposphere, stratosphere and mesosphere) on global time and spatial scales.One of possible regular mechanisms of vertical transport can be the well-known radiometric photophoresis. The developed theory forecasts, that for some types of soot aerosols the negative "solar" and positive "thermal" photophoresis (motion of particles in the field of outgoing thermal radiation) can result in levitation and vertical lifting of particulates against gravity in the upper troposphere-lower stratosphere.The results of theoretical and experimental investigations of so-called "accommodation" forces acting on particles with asymmetry of surface properties in rarefied gas in the directed electromagnetic radiation field (gravito-photophoresis) are presented. The estimations show that action of the investigated force is not capable to provide effective vertical transport of aerosol particles against gravity at altitudes of the lower and middle stratosphere.Among regular and effective mechanisms of aerosol transport it is necessary to note the vertical stratospheric wind. The unique opportunity of this analysis is given with a database of the research satellite UARS (1991-2005) together with the UKMO global circulation model of the middle atmosphere. It is shown that the vertical wind caused by specific long-term circulation of air masses in stratosphere and mesosphere can play a determining role in vertical transport of particles of any thermal-physics and optical properties at high altitudes.

AB - This study continues the analysis of the determining forces responsible for vertical aerosol transport in the middle atmosphere (upper troposphere, stratosphere and mesosphere) on global time and spatial scales.One of possible regular mechanisms of vertical transport can be the well-known radiometric photophoresis. The developed theory forecasts, that for some types of soot aerosols the negative "solar" and positive "thermal" photophoresis (motion of particles in the field of outgoing thermal radiation) can result in levitation and vertical lifting of particulates against gravity in the upper troposphere-lower stratosphere.The results of theoretical and experimental investigations of so-called "accommodation" forces acting on particles with asymmetry of surface properties in rarefied gas in the directed electromagnetic radiation field (gravito-photophoresis) are presented. The estimations show that action of the investigated force is not capable to provide effective vertical transport of aerosol particles against gravity at altitudes of the lower and middle stratosphere.Among regular and effective mechanisms of aerosol transport it is necessary to note the vertical stratospheric wind. The unique opportunity of this analysis is given with a database of the research satellite UARS (1991-2005) together with the UKMO global circulation model of the middle atmosphere. It is shown that the vertical wind caused by specific long-term circulation of air masses in stratosphere and mesosphere can play a determining role in vertical transport of particles of any thermal-physics and optical properties at high altitudes.

M3 - Conference contribution

SN - 978-88-95608-03-7

VL - 16

T3 - Chemical Engineering Transactions

SP - 337

EP - 344

BT - AAAS08: 2ND ADVANCED ATMOSPHERIC AEROSOL SYMPOSIUM

A2 - Ranzi, E.

PB - AIDIC-Italian Association of Chemical Engineering

CY - Milano

ER -