Jump to main content.

Emissions Modeling Clearinghouse
Biogenic Emission Sources

Biogenic emission sources are emissions that come from natural sources, and need to be accounted for in photochemical grid models, as most types are widespread and ubiquitous contributors to background air chemistry. Often only the emissions from vegetation and soils are included, but other relevant sources include volcanic emissions, lightning, and sea salt.

Biogenic emissions are typically computed using a model which utilizes spatial information on vegetation and land use and environmental conditions of temperature and solar radiation. The model inputs are typically horizontally allocated (gridded) data, and the outputs are gridded biogenic emissions which can then be speciated and utilized as input to photochemical grid models.

The research programs at EPA/ORD to measure and model these emissions are described in http://www.epa.gov/appcdwww/apb/biogenic.htm and http://www.epa.gov/asmdnerl/biogen.html. EPA's model is called the Biogenic Emission Inventory System (BEIS), which is described on the above webpages.

The current version of BEIS estimates volatile organic compound (VOC) emissions from vegetation and nitric oxide (NO) and carbon monoxide (CO) emissions from soils. Because of resource limitations, recent BEIS development has been incorporated into the Sparse Matrix Operational Kernel Emissions (SMOKE) system, so that the native version of BEIS is built within the SMOKE architecture.

The current version of BEIS, the BEIS3.12 model, requires a land use database known as the Biogenic Emissions Landuse Database, version 3 (BELD3). BELD3 data provides distributions of 230 vegetation classes at 1km resolution over most of North America. The data are for a specific grid; therefore, to use these data for input to BEIS3 on a specific grid, emissions modelers must further process these data. EPA/ORD has built the beld3smk program http://www.ie.unc.edu/cempd/projects/mims/spatial/smoke_bio_inputs.htmll) Exit EPA Disclaimer as part of the MIMS Spatial Allocator to convert the BELD3 data to various grids.

This web page provides ALL of the input files needed for the beld3smk program. To figure out which files you need to download, take the following steps using the table of data provided below:

| Office of Air Quality Planning & Standards | Technology Transfer Network |
| Clearinghouse for Inventories & Emissions Factors |

Local Navigation

Jump to main content.