Difference between revisions of "MEGAN biogenic emissions"

Revision as of 20:39, 25 February 2015

This page describes the implementations of the MEGAN (Model of Emissions of Gases and Aerosols from Nature) biogenic emissions in GEOS-Chem.

Overview

GEOS-Chem has used three versions of the MEGAN biogenic emissions. These are now all described on separate wiki pages.

MEGAN v2.0 biogenic emissions

The MEGAN v2.0 biogenic emissions are now obsolete. They were used in GEOS-Chem v8-02-03 and prior versions.

--Bob Y. 15:32, 25 February 2015 (EST)

MEGAN v2.1 biogenic emissions

The MEGAN v2.1 biogenic emissions were used in GEOS-Chem v8-02-04 through GEOS-Chem v9-02. They were retired with the advent of the HEMCO emissions component in GEOS-Chem v10-01.

--Bob Y. 15:32, 25 February 2015 (EST)

MEGAN v2.1 plus Guenther 2012 biogenic emissions

GEOS-Chem v10-01 and newer versions now use the MEGAN 2.1 biogenic emissions with updates from Guenther (2012); These are implemented throImplemented via the HEMCO emissions component.

--Bob Y. 15:32, 25 February 2015 (EST)

New Update Required in MEGAN algorithm

Chris Chan Miller found that the isoprene emissions in MEGAN do not capture the diurnal variability of isoprene observed in the Michigan state forest. This is because the meteorological variables input to GEOS-Chem (temperature and photosynthetically active radiation) are not interpolated between the 3-h average surface data read in to megan_mod.f. This can be fixed by including a CALL INTERP statement in main.f for I-3 met fields. Chris is working on updating this in his working code and will send necessary updates to Bob to be included in the standard code.

--Emarais 16:32, 4 April 2012 (EDT)

Update to MEGAN2.1 (Guenther et al., 2012)

Please see this file that describes an available update to MEGAN2.1 in GEOS-Chem. The update applies emission algorithm updates according to Guenther et al. (Geosci. Model Dev., 5, 1471–1492, 2012), enables computation of emissions for more compounds, uses CLM4 plant functional type distributions, facilitates computing emissions with different/dynamic land cover schemes, and streamlines the code.

Please contact Dylan Millet to obtain the code or with any questions.

Documentation:

• Readme

• Comparison between previous and updated BVOC emissions for standard tracers (year-2006):
  • 2x2.5
  • 4x5

• Comparison between previous and updated BVOC emissions for standard tracers (nested NA, year-2011):
  • 0.5x0.67

• Updated emissions for all BVOCs, including non-standard tracers:
  • 2x25

• Monthly CO comparison for previous and updated MEGAN implementation (year-2006; 4x5 resolution):
  • 4x5

--Dbm 14:18, 22 January 2013 (EST)

CO2 direct effect on isoprene emissions

This update is slated for inclusion in GEOS-Chem v10-01 or later

Amos Tai developed code updates to include CO2 inhibition of isoprene emissions in MEGAN.

The reference for this work is:

Tai, A.P.K., L.J. Mickley, C.L. Heald, S. Wu, Effect of CO2 inhibition on biogenic isoprene emission: Implications for air quality under 2000-to-2050 changes in climate, vegetation, and land use, Geophys. Res. Let., 40, 3479-3483, 2013. [pdf]

--Melissa Sulprizio 15:45, 23 January 2014 (EST)

Unresolved issues

None at this time.

References

1. Barkley, M., Description of MEGAN biogenic VOC emissions in GEOS-Chem, 2010. PDF
2. Buermann, W., Wang, Y.J., Dong, J.R., Zhou, L.M., Zeng, X.B., Dickinson, R.E., Potter, C.S., and Myneni, R.B.: Analysis of a multiyear global vegetation leaf area index data set, J. Geophys. Res., 107, 4646, doi:10.1029/2001JD000975, 2002.
3. Guenther, A., Baugh, B., Brasseur, G., Greenberg, J., Harley, P., Klinger, L., Serca, D., and Vierling, L.: Isoprene emission estimates and uncertainties for the Central African EXPRESSO study domain, J. Geophys. Res., 104, 30625-30639, 1999.
4. Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P.I., and Geron, C.: Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181-3210, 2006.
5. Guenther, A., and C. Wiedinmyer, User's guide to the Model of Emissions of Gases and Aerosols from Nature (MEGAN), Version 2.01, 2007.
6. Guenther, A. B., Jiang, X., Heald, C. L., Sakulyanontvittaya, T., Duhl, T., Emmons, L. K., and Wang, X.: The Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1): an extended and updated framework for modeling biogenic emissions, Geosci. Model Dev., 5, 1471-1492, doi:10.5194/gmd-5-1471-2012, 2012.
7. Millet, D.B., Jacob, D.J., Boersma, K.F., Fu, T.M., Kurosu, T.P., Chance, K., Heald, C.L., and Guenther, A.: Spatial distribution of isoprene emissions from North America derived from formaldehyde column measurements by the OMI satellite sensor, J. Geophys. Res., 113, D02307, doi:10.1029/2007JD008950, 2008. PDF
8. Mueller, J.-F., et al. Global isoprene emissions estimated using MEGAN, ECMWF analyses and a detailed canopy environment model, Atmos. Chem. Phys., 8, 1329-1341, 2008.
9. Myneni, R. B., et al., Large seasonal swings in leaf area of Amazon rainforests, Proceedings of the National Academy of Sciences, 104(12), 4820{4823, doi:10.1073/pnas.0611338104, 2007.
10. Palmer, P.I., Abbot, D.S., Fu, T.M., Jacob, D.J., Chance, K., Kurosu, T.P., Guenther, A., Wiedinmyer, C., Stanton, J.C., Pilling, M.J., Pressley, S.N., Lamb, B., and Sumner, A.L.: Quantifying the seasonal and interannual variability of North American isoprene emissions using satellite observations of the formaldehyde column, J. Geophys. Res., 111, D12315, doi:10.1029/2005JD006689, 2006. PDF
11. Sakulyanontvittaya, T., T. Duhl, C. Wiedinmyer, D. Helmig, S. Matsunaga, M. Potosnak, J. Milford, and A. Guenther, Monoterpene and Sesquiterpene Emission Estimates for the United States, Environ. Sci. Technol., 42(5), 1623{1629, doi:10.1021/es702274e, 2008.

--Bob Y. 09:39, 3 March 2010 (EST)