## TSD-1b Processing of Biogenic Emissions for OTC / MANE-VU Modeling

Bureau of Air Quality Analysis and Research
Division of Air Resources New York State Department of Environmental Conservation Albany, NY 12233

September 19, 2006Biogenic emissions for the time period from January 1, 2002 – December 31, 2002 were calculated by NYSDEC using the Biogenic Emi ssions Inventory System (BEIS) version 3.12 integrated within SMOKE2.1. General information about BEIS is available at http://www.epa.gov/AMD/biogen.html while documentation about biogenic emissions processing within SMOKE2.1 is available at http://cf.unc.edu/cep/empd/products/smoke/version2.1/html/ch06s10.html and http://cf.unc.edu/cep/empd/products/smoke/version2.1/html/ch06s17.html . Note that the SMOKE documentation refers to BEIS3.09 and has not yet been updated for BEIS3.12. This affects the number of species modeled as well as the use of different speciation profiles. However, the general processing approach has not changes from BEIS3.09 to BEIS3.12. In short, this processing approach is as follows and was utilized by NYSDEC for its biogenic emission processing for 8-hr ozone and PM 2.5 modeling:

1. Normbeis3 reads gridded land use data and em issions factors and produces gridded normalized biogenic emissions for 34 species/compounds. The gridded land use includes 230 different land use types. Both summer and winter emissions factors for each species/compound are provided for each of the 230 land use types. On output,
Normbeis3 generates a file B3GRD which contains gridded summer and winter emission fluxes for the modeling domain that are normalized to 30 °C and a photosynthetic active radiat ion (PAR) of 1000 μmol/m 2 s. In addition, gridded
summer and winter leaf area indi ces (LAI) are al so written to B3GRD

.

2. Tmpbeis3 reads the gridded, normalized emissions file B3GRD and meteorological
data from the MCIP-processed MM5 meteorologi cal fields generated by the University of Maryland for MANE-VU/OTC modeling. Specifically, the following MM5/MCIP meteorological variables are used by Tmpbeis3 to compute hourspecific, gridded biogenic emissions from the normalized emission fluxed contained
in B3GRD: layer-1 air temperature (“TA”), layer-1 pressure (“PRES”), total incoming solar radiation at the surfac e (“RGRND”), and convective (“RC”) and non-convective (“RN”) rainfall. A dditionally, the emissions for the 34 species/compounds modeled by BEIS3.12 are converted to CO, NO, and the CB-IVVOC species utilized in CMAQ via the use of the BEIS3.12-CB-IV speciation profile. In adition, an optional seasonal switch file, BIOSEASON , was utilized to
decide whether to use summer or winter em issions factors for any given grid cell on any given day. This file was generated by the SMOKE2.1 utility Metscan based on MM5 layer-1 air temperatures to determine the date of the last spring frost and first fall frost at each grid cell. Su mmer emission factors are used by Tmpbeis3 for the time period between the last spring frost and first fall frost at any given grid cell,
and winter emission factors are used for the remaining time period. Documentation
for the Metscan utility is available at http://cf.unc.edu/cep/empd/products/smoke/version2.1/html/ch05s07.html . An animated GIF file showing the BIOSEASON file used by NYSDEC can be found at ftp://ftp.dec.state.ny.us/dar/air_research/chogrefe/biog_reports/b3season_movie.gif

3. For reporting purposes, the hourly, speciated, gridded emissions were aggregated to the county level for each day. For any give n grid cell, emissions are distributed among the counties intersecting this grid cell in proportion to the area of each of these counties within the grid cell. Th e area gridding surrogates needed for this aggregration are based on a file obtained from EPA via http://www.epa.gov/ttn/chief/emch/spatial/new/bgpro.12km_041604.us.gz followed by windowing for the MANE-VU/OTC modeling domain.