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

CHAPTER 3. APPROACH
3.1. Alternative meteorological data to CMAQ
In order to respond to the increasing demand for better understanding of the
environment, air quality studies at different scales are required. For example, regional scale air
quality studies are needed for multi-state ozone transport, while small scale studies would
answer specific questions concerning domains on the size of metropolitan areas. The CMAQ
chemical transport model is designed to handle these scales of interest. However, the
meteorology input to the model have to adequately represent the atmospheric conditions at
these scales. This research is focused on providing an adequate alternative meteorological
input to the chemistry-transport model at small scales. So far, the meteorological input to
CMAQ has been supplied by MM5. MM5 simulations require highly skilled analysts which are
not generally available among the air quality modelers working in the regulatory community.
MM5 always has to be run separately by a meteorological team. As a matter of fact, coarse
resolution meteorological data are available in the meteorological research community and can
easily be provided for almost all episodes of interest. However, fine resolution data are not
widely available because of the computer time and resources involved.
This research suggests another way to obtain small scale meteorological data from
coarse resolution MM5 data instead of further running MM5 at fine resolution - a “prognostic-
diagnostic mix” approach (see Figure 1). We propose to use a “smart interpolator” to diagnose
the meteorological data from coarse resolution MM5 data. This process could save computer
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