- Simulations overview
- Mechanisms for full-chemistry simulations (e.g. Standard, Tropchem, etc.)
- Aerosol-only simulation
- CH4 simulation
- CO2 simulation
- Hg simulation
- POPs simulation
- Tagged CO simulation
- Tagged O3 simulation
- TransportTracers simulation
- 1 Overview
- 2 Recent science updates
- 3 Validation
- 4 References
- 5 Previous issues that are now resolved
This page contains information about the methane (CH4) simulation in GEOS-Chem.
Authors and collaborators
- Bram Maasakkers (Harvard)
- Melissa Sulprizio (Harvard)
- Jianxiong Sheng (Harvard)
- Yuzhong Zhang (Harvard)
- Tia Scarpelli (Harvard)
- Alex Turner (UC Berkeley)
Previous authors include:
- Kevin Wecht (formerly @ Harvard)
- Christopher Pickett-Heaps (formerly @ Harvard)
- Jerome Drevet (formerly @ EPFL)
- James Wang (formerly @ Harvard)
CH4 simulation user groups
Tagged CH4 simulation
In addition to the standard CH4 simulation, users may also choose to run the tagged CH4 simulation where methane species are tagged by emission source.
Recent science updates
The following updates were recently added into the GEOS-Chem CH4 simulation:
Updated CH4 simulation in v11-02 and later
This update was included in v11-02f (approved 17 May 2018).
Bram Maasakkers and Melissa Sulprizio have updated the CH4 simulation in GEOS-Chem v11-02. These updates include the following emission updates (brought in via HEMCO):
- EDGAR v4.3.2 global anthropogenic emissions
- Gridded US EPA emissions (Maasakkers et al. 2016)
- Canada and Mexico oil & gas emissions (Sheng et al. 2017)
- Daily QFED biomass burning emissions
- JPL WetCHARTs emissions (Bloom et al. 2017)
- Global geological seep emissions (Maasakkers et al., in prep)
- Global lake emissions (Maasakkers et al., in prep)
and code updates:
- CH4 loss by Cl (Maasakkers et al., in prep)
- GOSAT and TCCON observation operators (modified from the adjoint code)
The following data files are required for these updates
ftp://ftp.as.harvard.edu/gcgrid/data/ExtData/HEMCO/CH4/v2017-10/ (entire directory) ftp://ftp.as.harvard.edu/gcgrid/data/ExtData/HEMCO/MASKS/v2014-07/CONUS_Mask.001x001.nc ftp://ftp.as.harvard.edu/gcgrid/data/ExtData/HEMCO/MASKS/v2014-07/Canada_Mask.Extended_NAgrid.001x001.nc ftp://ftp.as.harvard.edu/gcgrid/data/ExtData/HEMCO/MASKS/v2014-07/Mexico_Mask.Extended_NAgrid.001x001.nc
A few caveats:
- EDGAR v4.3.2 lumps oil, gas, and coal emissions in the files available on their website. Ideally, we would like to separate these sources, so we are looking into that. In addition, Tia Scarpelli at Harvard is developing a global oil and gas CH4 emissions inventory which will be included in the future. Until we resolve this, the EDGAR v4.3.2 lumped oil/gas/coal emissions are added to CH4_OIL in the tagged CH4 simulation and CH4_GAS, CH4_COL only include emissions from Canada, US, and Mexico.
- EDGAR v4.3.2 rice emissions by default are annual emissions. For our CH4 simulations, we generated monthly EDGAR rice emissions by applying seasonality from the Zhang et al. (2016). We had to preprocess the EDGAR files to do this and haven't yet figured out a way to apply the seasonality via HEMCO -- it may require writing an extension. If you're interested in using our EDGAR seasonal rice emissions, please let us know and we can send you those files.
- We have updated rice emissions from Zhang et al. (2016), but we don't have permission to share those data yet. We used those rice emissions in Maasakkers et al. (in prep) to apply seasonality to the EDGAR v4.3.2 rice emissions.
- We recommend not use the lakes emissions (they are turned off by default in HEMCO_Config.rc). There is some concern it leads to double-counting when used together with WetCHARTS. It’s something we’ll look into but just using WetCHARTS for now is a cleaner approach.
- There’s a small issue with incorporating offshore GEPA emissions right now (as those fall outside of the US mask. We’re working on resolving that.
Update CH4 emissions to EDGAR v4.2
The CH4 simulation now uses emissions from the EDGAR v4.2 inventory.
In GEOS-Chem v10-01 and newer versions
In GEOS-Chem v10-01 and newer versions, EDGAR v4.2 CH4 emissions are read with the HEMCO emissions component. We have created new emission data files for the CH4 simulation (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. 13:23, 3 March 2015 (EST)
In GEOS-Chem versions prior to v10-01
Kevin Wecht has prepared EDGAR v4.2 emissions of methane for 2004-2008. The data files are available at:
ftp://ftp.as.harvard.edu/pub/geos-chem/data/GEOS_0.5x0.666_NA/CH4_201305/ ftp://ftp.as.harvard.edu/pub/geos-chem/data/GEOS_2x2.5/CH4_201305/ ftp://ftp.as.harvard.edu/pub/geos-chem/data/GEOS_4x5/CH4_201305/
You can download these directories with anonymous FTP or the Wget utility. For instructions, please see Downloading the GEOS-Chem data directories.
Modifications to subroutines RICE_EMIS and ASEASONAL_ANTHRO_EMIS in global_ch4_mod.F include changing the directory names and updating CYEAR and XTAU as follows:
WRITE( CYEAR, '(i4)' ) GET_YEAR() XTAU = GET_TAU0( 1, 1, GET_YEAR() ) IF ( GET_YEAR() .LT. 2004 ) THEN CYEAR='2004' XTAU = GET_TAU0( 1, 1, 2004 ) ENDIF IF ( GET_YEAR() .GT. 2008 ) THEN CYEAR='2008' XTAU = GET_TAU0( 1, 1, 2008 ) ENDIF
--Melissa Payer 16:53, 2 July 2013 (EDT)
- Bloom, A. A., Bowman, K. W., Lee, M., Turner, A. J., Schroeder, R., Worden, J. R., Weidner, R., McDonald, K. C., and Jacob, D. J.: A global wetland methane emissions and uncertainty dataset for atmospheric chemical transport models (WetCHARTs version 1.0), Geosci. Model Dev., 10, 2141-2156, https://doi.org/10.5194/gmd-10-2141-2017, 2017.
- Sheng, J.-X., D. J. Jacob, J.D. Maasakkers, M.P. Sulprizio, D. Zavala-Areiza, and S. Hamburg, A high-resolution (0.1ox0.1o) inventory of methane emissions from Canadian and Mexican oil and gas systems, Atmos. Environ., 158, 211-215, 2017. [PDF]
- Maasakkers, J.D., D.J.Jacob, M.P. Sulprizio, A.J. Turner, M. Weitz, T. Wirth, C. Hight, M. DeFigueiredo, M. Desai, R. Schmeltz, L. Hockstad, A.A. Bloom, K.W. Bowman, S. Jeong, and M.L. Fischer, Gridded national inventory of U.S. methane emissions, Environ. Sci. Technol., 50, 13123−13133, 2016. [PDF]
- Turner, A. J., Jacob, D. J., Wecht, K. J., Maasakkers, J. D., Biraud, S. C., Boesch, H., Bowman, K. W., Deutscher, N. M., Dubey, M. K., Griffith, D. W. T., Hase, F., Kuze, A., Notholt, J., Ohyama, H., Parker, R., Payne, V. H., Sussmann, R., Velazco, V. A., Warneke, T., Wennberg, P. O., and Wunch, D.: Estimating global and North American methane emissions with high spatial resolution using GOSAT satellite data, Atmos. Chem. Phys. Discuss., 15, 4495-4536, doi:10.5194/acpd-15-4495-2015, 2015.
- Turner, A. J. and Jacob, D. J.: Balancing aggregation and smoothing errors in inverse models, Atmos. Chem. Phys. Discuss., 15, 1001-1026, doi:10.5194/acpd-15-1001-2015, 2015.
- Wecht, K.J., D.J. Jacob, C. Frankenberg, Z. Jiang, and D.R. Blake, Mapping of North America methane emissions with high spatial resolution by inversion of SCIAMACHY satellite data, submitted to J. Geophys. Res., 2014.
- Wecht, K.J., D.J. Jacob, M.P. Sulprizio, G.W. Santoni, S.C. Wofsy, R. Parker, H. Bösch, and J.R. Worden, Spatially resolving methane emissions in California: constraints from the CalNex aircraft campaign and from present (GOSAT, TES) and future (TROPOMI, geostationary) satellite observations, Atm. Chem. Phys. Discuss., 14, 4119-4198, doi:10.5194/acpd-14-4119-2014, 2014.
- Wecht, K.J., D.J. Jacob, S.C. Wofsy, E.A. Kort, J.R. Worden, S.S. Kulawik, D.K. Henze, M. Kopacz, and V.H. Payne, Validation of TES methane with HIPPO aircraft observations: implications for inverse modeling of methane sources, Atmos. Chem. Phys., 12, 1823-1832, 2012.
- Pickett-Heaps, C.A., D.J. Jacob, K.J. Wecht, E.A. Kort, S.C. Wofsy, G.S. Diskin, D.E.J. Worthy, J.O. Kaplan, I. Bey, and J. Drevet, Magnitude of seasonality of wetland methane emissions from the Hudson Bay Lowlands (Canada), Atmos. Chem. Phys., 11(8), 3773-3779, doi:10.5194/acp-11-3773-2011, 2011.
- Wang, J.S., J.A. Logan, M.B. McElroy, B.N. Duncan, I.A. Megretskaia, and R.M. Yantosca, A 3-D model analysis of the slowdown and interannual variability in the methane growth rate from 1988 to 1997, Global Biogeochem. Cycles, 18, GB3011, doi:10.1029/2003GB002180, 2004.
Previous issues that are now resolved
The following bugs and/or issues with the code have now been resolved:
Add fixes for seasonal scale factors in CH4 simulations
Seasonal manure emissions
The seasonal scale factor files for rice and manure CH4 emissions are available for 2009-2015. The CH4 simulation will crash with a HEMCO error when running outside of that time range because HEMCO can't find a file for that year. To fix this, Bram Maasakkers has generated climatology scale factors for years outside that range. A new file EMICH4_Manure_ScalingFactors.WithClimatology.nc has been created and the climatology values have been added to years 2008 and 2016. That way, with the "C" cycling flag set the climatology scaling factors will be used outside of 2009-2015. The new file also combines the yearly files into a single file without $YYYY in the filename.
# Old entry in HEMCO_Config.rc: 10 MANURE_SF $ROOT/CH4/v2017-10/Seasonal_SF/EMICH4_Manure_ScalingFactors_$YYYY.nc sf_ch4 $YYYY/1-12/1/0 C xy 1 1 # New entry in HEMCO_Config.rc: 10 MANURE_SF $ROOT/CH4/v2017-10/Seasonal_SF/EMICH4_Manure_ScalingFactors.WithClimatology.nc sf_ch4 2008-2016/1-12/1/0 C xy 1 1
Seasonal rice emissions
Hannah Nesser noted considerable differences in rice emissions totals between 4x5 and 2x2.5 methane simulations. The issue was traced to the use of zero values in the rice scaling factors file, which caused issues when regridding the 0.1x0.1 degree scale factors to 4x5 and 2x2.5 resolution. To resolve the issue, a new file EMICH4_Rice_ScalingFactors.SetMissing.nc was created in which zero values are replaced with missing values.
# Old entry in HEMCO_Config.rc: 11 RICE_SF $ROOT/CH4/v2017-10/Seasonal_SF/EMICH4_Rice_ScalingFactors.nc sf_ch4 2012/1-12/1/0 C xy 1 1 # New entry in HEMCO_Config.rc: 11 RICE_SF $ROOT/CH4/v2017-10/Seasonal_SF/EMICH4_Rice_ScalingFactors.SetMissing.nc sf_ch4 2012/1-12/1/0 C xy 1 1