GISS Aerosol Microphysics: Susanne Bauer GISS, Dorothy Koch GISS and Robert McGraw BNL

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GISS Aerosol MicrophysicsSusanne Bauer (GISS),
Dorothy Koch (GISS) and Robert McGraw (BNL)
Motivation The GISS climate model, only included
a mass based aerosol scheme, allowing to
calculate the mass of sulfate (Koch et al JGR
99), nitrate (Bauer et al ACP 06), black and
organic carbon (Koch et al JGR 01) in one size
class, sea salt (Koch et al JGR 06) and dust
(Miller et al JGR 06) in a limited set of size
classes. Aerosol mixing was only considered
between dust, sulfate and nitrate (Bauer et al
JGR 06) due to condensation processes. The new
microphysical model (Bauer et al ACP 08) includes
the processes of secondary particle formation
(nucleation), coagulation and condensation, based
on the Methods of Moments Scheme. Tracking mass,
size and number concentrations and detailed
information on the aerosol mixing state.
Improvements for climate simulations Direct
Aerosol Forcing Explicit treatment of aerosol
size, chemical composition (mixing) and water
content. Indirect Aerosol Forcing Explicit
calculation of aerosol particle activation,
prognostic number concentrations. Interface for
the double-moment bulk cloud microphysics scheme.
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GISS Aerosol MicrophysicsSusanne Bauer (GISS),
Dorothy Koch (GISS) and Robert McGraw (BNL)
Example of detailed aerosol information as
simulated by the GISS model (Bauer et al,
submitted to Atmos. Chem Phys. 2008 The
Multiconfiguration Aerosol TRacker of mIXing
state MATRIX, an aerosol microphysical module
for global atmospheric models,)
Station Hohenpeissenberg, Germany Measurement of
Number and Size Distribution (black solid
line), GISS model number concentration (blue
line), mixing mode and chemistry (colored
symbols).