MODELS-3

DESCRIPTION

The primary goals for the Models-3 modeling system are to improve 1) the environmental management community's ability to evaluate the impact of air quality management practices for multiple pollutants at multiple scales, and 2) the scientist's ability to better probe, understand, and simulate chemical and physical interactions in the atmosphere. These two groups - the model user and the model developer -have very different requirements for a modeling framework. However, there are significant advantages in using the same problem solving environment. Thus, Models-3 is intended to serve as a community foundation for the widespread application of air quality models and for their continued scientific advancement.

Models-3 is not a single model or modeling system, but rather it is a problem solving environment containing components that help you build, evaluate, and apply air quality models. The initial version of Models-3 contains a Community Multiscale Air Quality (CMAQ) modeling system for urban to regional scale air quality simulation of tropospheric ozone, acid deposition, visibility and fine particulate.

Models-3 and CMAQ in combination form a powerful third generation air quality modeling and assessment system. First generation air quality models dealt with tropospheric air quality with simple chemistry at local scales using Gaussian plume formulation as the basis for prediction. Second generation models covered a broader range of scales (local, urban, regional) and pollutants, addressing each scale with a separate model and often focusing on a single pollutant. Third generation models treat multiple pollutants simultaneously up to continental scales and incorporate feedbacks between chemical and meteorological components.

Future efforts toward fourth generation systems will extend linkages and process feedback to include air, water, land, and biota to simulate the transport and fate of chemical and nutrients throughout an ecosystem.

The EPA Models-3 Web site provides details on model components and operation.

SCALE AND AREAS OF APPLICATION

SURVEY COMMENTS

Only one survey respondent reported using Models-3 and did not provide an evaluation of its effectiveness.

BENEFITS (PROS)

COSTS (CONS)

RECOMMENDATIONS