Alternative small scale meteorology input to a chemical transport ...

treat independently. Proper modeling of these air pollutants requires that the broad range of
temporal and spatial scales of multi-pollutant interactions be considered simultaneously. Another
key aspect of the “one atmosphere” perspective is the dynamic description of the atmospheric
processes.
Previously, many meteorological models have been built with limited atmospheric
dynamics assumptions. To simplify the model development process, the governing equations
were first simplified to match the target problems, then computer codes were developed. This
approach enabled rapid development of models. However, to provide the scalability in
describing atmospheric dynamics, a fully compressible governing set of equations is preferable.
For successful “one atmosphere” simulations, it is imperative to also have a constant algorithmic
linkage between meteorological and chemical transport models.
2.3. The latest state-of-the-science chemical transport model CMAQ
The result of six years devotion and scientific efforts to accomplish the “one
atmosphere” goal is the Community Multi-scale Air Quality Model (CMAQ), called also
CMAQ Chemical Transport Model (CCTM).
The most important requirement of the CMAQ modeling system is to maintain a
consistent description of the atmosphere for different meteorological and chemical transport
models. Various coordinate systems are used in the meteorological models. Selection of a
suitable coordinate system is an important step of model formulation. If a Chemical Transport
Model (CTM) can be formulated and coded using a generalized coordinate system, it would be
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