Perspective on Air Quality and Dispersion Modeling Tools for Advanced Urban and Coastal Applications

The urban and coastal environments present a number of challenges for air quality and emergency response modeling applications. For example, in the urban environment, human activities significantly impact the planetary boundary layer itself through dramatic changes in the land surface and energy balance. These anthropogenic effects can influence atmospheric motion across micro- to meso-scales, contributing to a complex environment that can be difficult to capture in a single air quality dispersion model. Coastal environments also present a challenge as the unique meteorology created by the land/water discontinuity is difficult to accurately simulate for purposes of predicting atmospheric pollutant concentrations. Significant temporal and spatial variations of boundary layer properties within these complex environments, coupled with a growing need for integrated exposure and risk-based approaches to health and environmental impact assessments, place higher demands on dispersion model skill that will be difficult to meet. Likewise, the potential threat to homeland security affecting large populations residing in these urban environments has motivated an upsurge in demand for improved tools to support emergency response activities. Thus, effective air quality management of urban environments in the future will require integrated approaches that encompass multiple pollutants, multiple scales of motion, and multiple pathways of exposure. A review of existing tools and suggested advanced approaches will be presented to illustrate current and futures capabilites and their issues.