ABSTRACT
Today, we are confronted with increasingly more sophisticated application requirements for urban modeling. These include those that address emergency response to acute exposures from toxic releases, health exposure assessments from adverse air quality, energy usage, and characterizing and potential amelioration of heat islands relevant to human sustainability issues. We contend that their requirements cannot be adequately met with simplistic one size fits all atmospheric models primarily due to combination of wide range of scales and complexities of urban structures and land uses. In this context, this chapter provides an overview of modeling scale dependent meso-tourban scale flows and air quality. Typical modeling methods and approaches for urban modeling in current use are reviewed, the implications and limitations are presented, and the unique features of the urban canopy layer are highlighted. Various new advanced modeling approaches and a generalized model framework able to take advantage of detailed parameterizations from emerging databases with gridded fields of canopy parameters
and anthropogenic heating to support current canopy implemented simulation schemes follow. The urbanized versions of the Weather Research and Forecasting (WRF) model are then described and illustrative examples of both meteorology and air quality modeling are provided to demonstrate a range of urban focused applications followed by discussion of challenges and opportunities for urban modeling.
