Aircraft emissions

This page describes the aircraft emissions inventories used by GEOS-Chem.

FAA aircraft emissions inventory

Starting with GEOS-Chem v9-01-02, we have implemented monthly mean aircraft emissions from the from the FAA AEDT emissions inventory v2.0. This inventory was developed by the FAA and was adapted for GEOS-Chem by Steven Barrett, Steve Yim, Jamin Koo, Akshay Ashok et al from MIT.

This inventory contains the following species:

1. Fuel burned
2. CO
3. Hydrocarbons (not included into GEOS-Chem)
4. NOx
5. Soot (i.e. black carbon)
6. Organics (i.e. organic carbon)

BC and OC are derived from the soot & organics. SO2 and SO4 are derived from the total fuel burned.

Running GEOS-Chem with the FAA AEDT v2.0 emissions gives us the following annual totals:

 NOx:  0.8118 Tg N
  CO:  0.6329 Tg    (troposphere only)
 SO2:  0.2212 Tg
 SO4:  0.0068 Tg
BCPI:  0.0059 Tg C
OCPI:  0.0061 Tg C

For more information, please see this validation document (by Bob Yantosca) which describes how the FAA/AEDT emissions were implemented into GEOS-Chem.

--Bob Y. 15:15, 9 June 2011 (EDT)

Old aircraft emissions inventory (prior to v9-01-02)

NOx

The inventory of aircraft NOx used in GEOS-Chem is described in Wang et al [1998]:

For NO emissions from subsonic aircraft, we adopted the 1992 monthly mean emisison inventory compiled by Baughcum et al [1996] and Metwally [1995]; the inventory has a resolution of 1° x 1° x 1 km, and the global source is 0.51 Tg N/yr.

The source code to read data from the aircraft NOx emissions inventory is aircraft_nox_mod.f. Routine READAIR reads the files from disk at the start of each new month, and routine AIREMISS interpolates from the 1km vertical grid to the GEOS-3, GEOS-4, GEOS-5, or GCAP vertical grid.

For more information about the data files, please see the following READMEs:

1. GEOS_0.5x0.666_CH/aircraft_NOx_200202/README
2. GEOS_2x2.5/aircraft_NOx_200202/README
3. GEOS_4x5/aircraft_NOx_200202/README

--Bob Y. 16:27, 25 February 2010 (EST)

Known issues

Due to the common block error described by Lee Murray, in GEOS-Chem v7-04-13 we have added a new module array (EMIS_AC_NOx) to "aircraft_nox_mod.f". The EMIS_AC_NOx array will be referenced in routine "setemis.f", which will pass the aircraft NOx emissions to the SMVGEAR solver. The old common-block array "GEMISNOX" will be removed.

SO2

From Park et al [2004]:

Other anthropogenic sources of SO2 in the model include gridded monthly aircraft emissions (0.07 Tg S/yr) taken from Chin et al. [2000a] ...

The aircraft emissions for SO2 are read from disk by routine READ_AIRCRAFT_SO2 in module sulfate_mod.f.

For more information about the data files, please see the following READMEs:

1. GEOS_0.5x0.666_CH/sulfate_sim_200508/README
2. GEOS_0.5x0.666_NA/sulfate_sim_200508/README
3. GEOS_2x2.5/sulfate_sim_200508/README
4. GEOS_4x5/sulfate_sim_200508/README

--Bob Y. 16:45, 25 February 2010 (EST)

References

1. Barrett, S., et al, Guidance on the use of AEDT Gridded Aircraft Emissions in Atmospheric Models Version 2.0, Federal Aviation Administration, Washington DC, August 17, 2010. PDF
2. Baughcum, S.L., T.G. Tritz, S.C. Henderson, and D.C. Pickett, Scheduled civil aircraft emission inventories for 1992: Database development and analysis, NASA CR-4700, Nat. Aeronaut. and Space Admin., Washington DC, 1996.
3. Chin, M., P. Ginoux, S. Kinne, O. Torres, B. Holben, B. N. Duncan, R. V. Martin, J. A. Logan, A. Higurashi, and T. Nakajima, Tropospheric aerosol optical thickness from the GOCART model and comparisons with satellite and sunphotometer measurements, J. Atmos. Sci., 59, 461–483, 2002.
4. Metwally, M, Jet aircraft engine emissions database development--1992 military, charter, and nonscheduled traffic, NASA CR-4684, Nat. Aeronaut. and Space Admin., Washington DC, 1995.
5. Park, R. J., D. J. Jacob, B. D. Field, R. M. Yantosca, and M. Chin, Natural and transboundary pollution influences on sulfate-nitrate-ammonium aerosols in the United States: implications for policy, J. Geophys. Res., 109, D15204, 10.1029/2003JD004473, 2004. PDF
6. Wang, Y., D.J. Jacob, and J.A. Logan, Global simulation of tropospheric O3-NOx-hydrocarbon chemistry, 1. Model formulation, J. Geophys. Res., 103, D9,10,713-10,726, 1998. PDF

--Bob Y. 13:46, 4 April 2011 (EDT)