AEROSOLS, CLOUDS, CHEMISTRY AND RADIATIVE FORCING
On-going Research at VTech* in collaboration with
Battelle, Pacific Northwest Laboratories
( Leaders: Steven J. Ghan and Richard C. Easter )
and Georgia Institute of Technology
( Leader: Rick D. Saylor )
A detailed global tropospheric chemistry:
gaseous species
and aqueous species
and aerosol model
that predicts
concentrations of oxidants: e.g. gaseous Hydrogen peroxide$
, and hydroperoxylradical$ ; as well as aerosols:
e.g. Methane sulfonic acid (MSA) component of
the Aitken mode$ ,
and MSA component of the accumulation mode$ ;
and aerosol precursors: e.g.
sulfure dioxide$ , and
Dimethyl Sulfide (DMS)$ ,
coupled to a general circulation model that predicts both
cloud water mass$ ,
and cloud droplet number$ will be further developed
( the current model be referred as a simplified chemistry model and the
further developed model be referred as a comprehensive chemistry model ),
evaluated, and then used to estimate the
direct and indirect radiative impact of
anthropogenic aerosols .
Both number and mass of several
externally-mixed aerosol size modes will be predicted, with internal
mixing assumed for the different aerosol components within each mode.
Aerosol species to be predicated include sulfate in all aerosol size modes: e.g.
sulfate in the Aitken mode$ and
sulfate in the accumulation mode$ ; carbonaceous,
nitrate, soil dust$ , and
sea salt$ .
Parallel simulations with and without
anthropogenic aerosol will be performed for a global domain.
Physically-based models will be used to estimate aerosol radiative
properties (including dependence on relative humidity) and aerosol
activation as cloud condensation nuclei ( e.g. number activation rate for
Aitken mode$ ,
accumulation mode$ , and
coarse mode$ ).
The simulated aerosol optical
depth and droplet effective radius will be compared with satellite
observations.
*Leonard K. Peters : e-mail peters@vt.edu; Pius C.S. Lee : e-mail piuslee@vt.edu
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