Aircraft emissions

---

---

GEOS-Chem v11-02-final will also carry the designation GEOS-Chem 12.0.0. We are migrating to a purely numeric versioning system in order to adhere more closely to software development best practices. For a complete description of the new versioning system, please see our GEOS-Chem version numbering system wiki page.

---

---

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

MIT aviation emissions inventory

This update was tested in the 1-month benchmark simulation v9-02n and approved on 12 Aug 2013.

Monthly mean aircraft emissions were generated based on 2005 scheduling data from the Aviation Emissions Inventory v2.0, developed by Nick Simone and based on research by Marc Stettler under Steven Barrett. These were implemented into GEOS-Chem by Sebastian D. Eastham.

The following are gridded at a horizontal resolution of 1° x 1°. The emissions are vertically resolved in 60.9 m (200 ft) increments up to 1000 ft, and 1000 ft increments beyond that. The emissions are stored in NetCDF files and read in by aeic_mod.F:

1. Fuelburn
2. CO
3. Hydrocarbons
4. NOx

Black and organic carbon (BC/OC) are determined based on an emissions index of 0.03 g/kg fuel burn; sulfur emissions (sulfur dioxide and sulfates) are calculated assuming a fuel sulfur content of 600 ppm by mass and a sulfur conversion efficiency of 2%. The older aircraft NOx emissions have been removed wholesale, while the older sulfur emissions are enabled if AEIC emissions are disabled.

--Sebastian D. Eastham 15:15, 9 June 2011 (EDT)

Implementation via HEMCO

In GEOS-Chem v10-01 and newer versions, the AEIC aircraft emissions are implemented via the HEMCO emissions component. We have created new AEIC data files (in COARDS-compliant netCDF format) for use with HEMCO. These new data files are contained in the HEMCO data directory tree. For detailed instructions on how to download these data files to your disk server, please see our Downloading the HEMCO data directories wiki post.

--Bob Y. 13:17, 3 March 2015 (EST)

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

These emissions are no longer compatible with GEOS-Chem and have since been retired. The HEMCO emissions component now reads the AEIC aircraft emissions data from netCDF files. The binary punch file format is being retired from GEOS-Chem.

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. 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.
2. 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.
3. 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.
4. 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
5. 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
6. Stettler, M.E.J., S. Eastham, S.R.H. Barrett, Air quality and public health impacts of UK airports. Part I: Emissions, Atmos. Environ., 45, 5415-5424, 2011.

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