What We Do
Atmospheric Chemical Mechanism Development
Chemical mechanisms are at the heart of
atmospheric chemistry models, representing the complex reactions occurring in the atmosphere.
The accuracy of model predictions depends significantly on how well
these mechanisms approximate real atmospheric processes. As our
scientific understanding evolves, it is crucial to update these
mechanisms continuously.
One of our key efforts is the
development of a new chemical mechanism called MOZART-TS3, designed
to improve the representation of alkane chemistry, which has been
simplified in existing mechanisms like
MOZART-TS1
and
MOZART-TS2. MOZART-TS3 introduces 149 kinetic and 21 photolysis reactions,
covering a broader spectrum of chemical processes. These include the
initial reactions of alkanes with OH, interactions of peroxy
radicals with NO, HO₂, and NO₃, permutation reactions among peroxy
radicals, alkoxy radical decomposition, hydrogen shifts, and more.
To achieve this, we have been collaborating closely with
experts in
chemical
reactions
and the
organic gas
measurement
team.
Multi-Scale
Earth System Modeling
Simulations of the Earth and its atmosphere typically use either
global or
regional
models. While global models often lack the resolution to capture
nonlinear processes accurately, regional models address this with
finer horizontal resolution. However, they rely on boundary
conditions from global models, which can introduce inconsistencies
due to differences in chemistry, speciation, emissions, and more.
Additionally, maintaining consistent simulations for long-lived
species across regional domain boundaries remains challenging.
The Multi-Scale Infrastructure for Chemistry and Aerosols
(MUSICA)
will become a computationally feasible global modeling framework
that allows for the simulation of large-scale atmospheric phenomena
while still resolving chemistry at emission and exposure-relevant
scales (down to ~1 km within the next 5 years). Currently, MUSICA
(version 0) is available as a configuration of
CAM-chem, the Community Atmosphere Model with Chemistry, which is a component of the
Community Earth System Model (CESM).
We developed a custom MUSICA grid to simulate Korea at a ~7 km
resolution, while simultaneously simulating the globe at a ~100 km
resolution.
This approach enables capturing small urban areas in South Korea and
allows for seamless two-way feedback between Korea and the global
scale processes. Additionally,
it closely aligns with the GEMS satellite pixel resolution of 7
km × 7.7 km over Seoul, facilitating the integration of satellite
observations with the modeling framework.
Climate and Health Impact Assessment
While it is clear that
reducing air pollutants is beneficial
for human health,
the risk models used to estimate health effects still have a lot
of limitations and uncertainties. Furthermore, some air quality improvement measures could lead to
disbenefits for near-term climate change. The full extent of these
trade-offs when integrating air quality and climate change
mitigation policies has not yet been fully addressed. On the other
hand,
aerosols, unlike long-lived greenhouse gases, are unevenly distributed,
which means
their health and climate effects are strongly influenced by the
location of their sources, chemical transformations, and loss
processes.
These interactions are bidirectional:
climate influences aerosol concentrations through changes in
temperature and radiation, while aerosols impact the climate
by directly
blocking sunlight
or
altering cloud
properties. Although these processes are closely linked to our future,
estimating their effects is highly complex due to numerous
uncertainties in aerosol chemistry, optics, cloud microphysics,
biogenic emissions, anthropogenic activities, and more. We are
continuously improving scientific methods and breaking down the
various factors to better assess the climate and health impacts of
air pollutants.
