Role of aqueous aerosol in the build up of large upper tropospheric moisture

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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
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Contents Introduction - observational data of
UT moisture - water activity criterion Approach
es 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
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Observations of UT moisture
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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/cl4/yosoku/yosoku-en.htm
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Water activity criterion
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Maximum RHi of aqueous aerosol droplets which is
allowed by a water activity criterion (WAC).
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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 Raoults law pA XA pA is applied
for A. In the region where XA ? 0, we have the
Raoults law pB XB pB for B component.
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,
Water activity may be approximated as
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Cubic ice hypothesis
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Hexagonal ice
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The arrangement of water molecules in hexagonal
ice
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Hexagonal ice lattice
Cubic ice
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Diffraction patterns from frozen emulsified
droplets of 30 wt HNO3.
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Ratio of vapor pressure of cubic and hexagonal
ices
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The hypotheses of organic coating around sulfuric
acid aerosol
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Organic coating of sulfuric acid aerosol
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The hypotheses of concentrated glassy citric acid
aerosol
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Calorimetric thermograms of emulsified 17 wt
H2SO4 and 17/3 wt H2SO4/HNO3.
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Complete and truncated thermograms of 20wt H2SO4.
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Cooling
Droplets are on hydrophobic surface.
50 µm
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Cooling
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Cooling
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Cooling
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Cooling
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Cooling
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Cooling
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Cooling
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Warming
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Warming
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Warming
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Warming
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Warming