Modeling Tools and Resources

Modeling Tools

The District utilizes various tools in conducting research. Links are provided to the sources of these tools for additional information.

Emissions processing tools
To prepare model-ready emissions inventories for both the CMAQ and CAMx models, the following tools are being used:

• Emission Modeling System 1995 (EMS95)
• Sparse Matrix Operator Kernel Emission (SMOKE) model

Meteorological modeling tools
To prepare meteorological inputs to air quality models, the following tools are being used:

• Mesoscale Meteorological Model V5 (MM5)
• Weather Research and Forecasting (WRF) Model
• California Meteorological Model (CALMET)

Air quality models
Air quality models, also known as photochemical models, are used for evaluating the effectiveness of proposed emission control strategies, planning purposes and preparation of State Implementation Plans for both ozone and PM. The District currently uses two photochemical models. The U.S. EPA’s Community Multiscale Air Quality (CMAQ) model is being used for PM modeling and Environ International Corporation’s Comprehensive Air Quality Model with extensions (CAMx) is being used for ozone and toxics modeling. For the purpose of multi-pollutant research, efforts are underway to simulate all three types of pollutants with CMAQ. Follow these links for more information on:

• Comprehensive Air Quality Model with extensions (CAMx)
• Community Multiscale Air Quality (CMAQ) Model

In addition, District staff apply air quality dispersion models to study the impacts of localized sources. The CALPUFF modeling system, which includes CALMET (see above), is the primary tool in these studies. More information is available at:

Health impacts assessment tools
To evaluate the public health impacts of current pollutant levels and estimate the benefits of control measures and strategies, the District relies on modeling tools which relate changes in ambient air quality to health outcomes. These tools include the following models:

• Environmental Benefits Mapping and Analysis Program (BenMAP)
• Stochastic Human Exposure and Dose Simulation (SHEDS) Model

Modeling Computer Resources

The District has a 120-processor Linux cluster computer system to perform modeling. In addition, each modeling staff member has a Linux computer in his/her office to access the cluster computer system.