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 EPA supports development of specific biogenic emissions tools. The links below provide access to those tools, landuse input data, and associated documentation.
Refer to the CMAS Center Spatial Allocator page and use the link for Raster Tools on that page for instructions regarding access and use of the BELD4 data.