Environmental Engineering Reference
In-Depth Information
as dust storms, convective thunderstorms, intense lightning and hurricanes is
strongly connected to understanding and modeling such effects. The present work
focuses on the feedbacks between air pollution and meteorology. Under certain
weather conditions such processes must be adequately resolved because they
affect the removal processes and therefore define the air pollution levels. The role of
tropospheric aerosols in atmospheric processes and implications on air quality is
examined for a test case over Eastern Mediterranean.
2. Model Description
ICLAMS has been developed by the Atmospheric Modeling and Weather
Forecasting Group at the University of Athens (AMWFG), in order to be used as a
research and forecasting tool for air pollution and climate applications at the
framework of CIRCE project. The new developed modeling system is based
on RAMS6.0 [3]. ICLAMS capabilities have been extended with the addition of
a detailed air-quality scheme including desert-dust [4], sea-salt spray [5] and
anthropogenic pollutants parameterization, online coupled with gas and aqueous
phase chemistry modules. The chemical component of the model constitutes of
the gas and aqueous chemistry module and the gas-particle interaction module.
The gas chemistry module is based on the chemistry mechanism SAPRC99. The
photochemical scheme uses basic formulations and it is directly coupled with
the radiation scheme of RAMS. The aqueous chemistry module deals with the
chemical processes that take place inside a cloud. For the gas-aerosol processes
the ISORROPIA mechanism is incorporated into the model. The original lookup
table approach of cloud droplet nucleation in RAMS has been replaced by the
FNS (Fountoukis-Nenes-Seinfeld) cloud droplets nucleation formulation [6, 7].
The rest of the microphysics package remains the same as in original RAMS
model.
The main mechanisms through which particles and gas pollutants are removed
from the atmosphere are the dry and wet deposition. Dry deposition velocities
are calculated from gravitational settling and surface resistances. Wet deposition
mechanism is responsible for the larger amount of natural and anthropogenic
pollutants removal, especially away from the sources and is strongly connected to
the precipitation process. The parameterization scheme for the wet deposition
describes the removal of the particles from the atmosphere through in-cloud and
below-cloud scavenging. ICLAMS has been used for studying effects of dust and
seasalt on cloud formation in the Mediterranean.
