Urbanization has a tremendous impact on air quality, both
over the city and the surrounding countryside. Air quality attainment becomes
a critical problem, and is exacerbated by urban growth. Increased surface
temperatures over the city are directly related to an increase in ozone
production. Measurement of thermal energy characteristics across the urban
landscape, therefore, can be input into air quality models, such as the
Urban Airshed Model (UAM) to predict the spatial distribution of photochemically
active pollutants, including ozone.
Urban Airshed
Model - More Information
Air quality models are designed to simulate the transport, reaction,
emission, and deposition of air pollutants. The scale of models used in
LBNL's urban heat island mitigation work is similar to that of mesoscale
meteorological models.
Typical input to air quality models consists of meteorological conditions
and emission inventories that provide information on the spatial distribution
and rates of emissions of pollutants from power plants, point sources, area
sources, mobile sources, and vegetation. Other inputs relate to surface
characteristics such as vegetative refraction and roughness.
Typical output from air quality models includes the four-dimensional
distribution of pollutant concentrations such as those of ozone, nitrogen
dioxide, carbon monoxide and dioxide, and others. In past modeling efforts,
LBNL has found that the meteorological and air quality models, although
not entirely free of errors, predict reasonably well the observed states.
However, the data suggest that further model improvements and input modification
may be needed to enhance the prediction capability of these models. |
