Role of aqueous aerosol in the build up

Role of aqueous aerosol in the build up of large upper tropospheric moisture Anatoli Bogdan Institute of Physical Chemistry, University of Innsbruck Austria and Department of Physics, University of Helsinki Finland

Contents Introduction - observational data of UT moisture - water activity criterion Approaches for explanation of large UT moisture - cubic ice hypothesis - organic coating around sulfuric acid aerosol - glassy organic (citric acid) aerosol - mixed-phase cirrus cloud particles

Observations of UT moisture

The warming is large at the upper troposphere in the tropics and the lower troposphere in the northern high latitude. http: //www. mri-jma. go. jp/Dep/cl/cl 4/yosoku-en. htm

Water activity criterion

Maximum RHi of aqueous aerosol droplets which is allowed by a water activity criterion (WAC).

Equilibrium partial pressures of the components of ideal and non-ideal binary solution as a function of the mole fraction XA. When XA → 1, we have a dilute solution of B in A. In this region the Raoult’s law p. A = XA p*A is applied for A. In the region where XA → 0, we have the Raoult’s law p. B = XB p*B for B component.