Biofuel emissions

01 Nov 2004

Here is the original README file by Rynda Hudman that describes the creation of the EPA/NEI99 emissions files (both anthropogenic and biofuel) that are stored in the EPA_NEI_200411 directory:

NEI99 Emission Inventory README (rch 11/1/04)

1. These files were created from NEI99 regridded emissions originally at .25X.25 resolution. These files can be found /data/epa_data. Please see README file in this directory for original file info.

The following emission types are included in the NEI99 inventory.

Anthropogenic

cow/

household_solvents/

power/

aircraft/

fertilizer/

industrial/

fowl/

industrial_solvents/

residential_fossil/

hogs/

other/

transport/

Biofuel

residential_biomass/

Not updated but available in inventory

biogenic/

biomass/

Procedures Document for Emission Inventory can be found in the group library

1. The files are large and as such were preprocessed into hourly files using extract_epa.pro of the format: e.g., temp_cow_average.1999jul.wkend_avg.24.gz. These files can be found at /data/epa_data/EPA_TEMP/
2. These files were then summed over a day, summed over each source type and converted into molec/cm2/s --> to get anthropogenic and biofuel emissions for each month and regridded to 1X1 using read_regrid_epa.pro.
3. These files were then scaled. All emissions were kept as is except for the following anthropogenice emissions (not biofuel)
   Propane(19), Ethane(21), and Acetone(9) are scaled by X6.4, X2.5, and X3 respectively to match prior emissions
   if tracerin(i) eq 19 then scalefactor = 6.4d0
   if tracerin(i) eq 21 then scalefactor = 2.5d0
   if tracerin(i) eq 9 then scalefactor = 3.0d0
   It is well-known that this inventory likely underestimates many VOCs.
   This scaling was done using scale_to_geos_anthro.pro and scale_to_geos_bf_new.pro
4. These emissions were then regridded using regrid_biofuel.pro and regrid_anthro.pro to create the files in 2X25 and 4X5
5. A mask over the U.S.(1=in U.S. and 0=not in U.S.) is used to implement these emissions since we do not have original global emission files. NEI99 is used in boxes exclusively U.S., those boxes which have Canadian and Mexican emissions are left as previous 1998 emissions.
6. NEI99 includes both weekend and weekday emissions and those are implemented here. Diurnal scaling is done as before in GEOS-CHEM.