SIP Baseline Emission Inventory Projections

This page updated October 7, 2011

(For Regions in the CCOS Domain)

Link to: Table of Contents


Welcome to the SIP/CCOS Baseline Emission Inventory Projections web site for the CCOS domain!

This site has been prepared to assist ARB and district staff in the timely retrieval of emissions inventory information to aid in the SIP development process.

The SIP/CCOS emission inventory and associated emissions projections are developed jointly by the California Air Pollution Control and Air Quality Management Districts and the California Air Resources Board (ARB). The California Emission Forecasting System (CEFS) is the computer tool used to develop the projections and the emission estimates are based on the most currently available growth and control data available at the time of the forecast runs. For mobile sources, CEFS integrates the emission estimates from the EMFAC model and the OFFROAD model to provide a comprehensive anthropogenic emission inventory. Biogenic emission estimates are developed by ARB using the BEIGIS model.

This web site offers several report query tools that enable the user to retrieve "customized" emissions data by major source category for annual average, summer seasonal average, and winter seasonal average periods. Although the web site was originally intended to cover the CCOS domain, the extents of the domain cover most of the geographic area of California, so the projections include estimates for the entire state. The seasonal emission projections presented on the SIP/CCOS emission web site are intended for ARB and district staff use in the development of SIPs for all areas except those falling in the SCOS domain (SCOS and CCOS modeling boundary map).

Modeling inventory projections are also developed by CEFS for specific months for typical weekday and weekend periods for input to photochemical models. Modeling inventory projections include facility level emissions and spatial information (e.g. UTM coordinates for point sources) necessary for developing gridded inventories for input to the air quality models. Summaries of modeling inventories for various episodes are included on this web site for retrieval.

Note: On-Road mobile sources are not included in these projections as the modeling inventories for these sources are created using DTIM.

The "Table of Contents" lists the report query tools and documentation elements associated with the SIP/CCOS emissions projections web site. Because of the dynamic nature of SIP development, the emission inventories are updated on a continual basis. Thus, documentation and version-control are critical components of this web tool. The most current versions of the web query tools are listed at the top and these versions should be used for all current work wherever possible (in some cases, a new version may be under development and contain only data for specific regions of the state—in these cases, there will be a message listed at the top of the report entry page). Other versions are retained as needed to link key data products with particular projects (e.g. a "draft" version of a SIP).

Questions pertaining to this web site should be directed to Martin Johnson of ARB’s Emission Inventory Branch. Detailed documentation of most recent updates incorporated in the inventory and associated growth and control data are available from Martin Johnson.