Scale factors for anthropogenic emissions

This page describes the methodology of the interannual scaling factors used for anthropogenic emissions in GEOS-Chem. In general, the various emissions inventories are for a particular year (or in some cases, for multi-years). A set of scale factors is required to adjust the emissions totals to what the

Overview

From van Donkelaar et al., [2008]:

We scale all regional and global inventories from their respective base year to 2003, the last year of available statistics, unless its base year is after 2003. Our approach follows Bey et al. (2001) and Park et al. (2004). Emissions are scaled according to estimates provided by individual countries, where available. These countries/regions include the United States, Canada, Japan and Europe. NOx emissions of remaining countries are scaled proportional to changes in total CO2 emissions. SOx emissions are similarly scaled to solid fuel CO2 emissions and CO emissions to liquid fuel CO2 emissions. CO2 emission data are obtained from the Carbon Dioxide Information Analysis Center (CDIAC).

Philippe Le Sager wrote:

Note that the scale factor have been updated since van Donkelaar et al [2008] to go up to 2005, and are based on REAS data now for South East Asia: Relative changes in the REAS inventory (Ohara et al., ACP, [2007]) over East Asia have been used.

This should be a good improvement as REAS emissions are gridded, rather than national scale emissions, giving us much better spatial detail. Also, these scalars are now based on actual NOx, SOx and CO emission estimates, not strictly an assumed proportionality between total, solid and liquid CO2 emissions.

References

1. Anthropogenic emissions inventories in GEOS-Chem v8-02-03 (and higher versions)
2. Anthropogenic emissions inventories used in GEOS-Chem v8-01-04 thru v8-02-02
3. Anthropogenic emissions inventories prior to GEOS-Chem v8-01-01
4. Ohara, T., H. Akimoto, J. Kurokawa, N. Horii, K. Yamaji, X. Yan, and T. Hayasaka, An Asian emission inventory of anthropogenic emission sources for the period 1980–2020, Atmos. Chem. Phys.,, 7, 4419-4444, 2007. ACP site
5. van Donkelaar, A., R. V. Martin, W. R. Leaitch, A.M. Macdonald, T. W. Walker, D. G. Streets, Q. Zhang, E. J. Dunlea, J. L. Jimenez, J. E. Dibb, L. G. Huey, R. Weber, and M. O. Andreae, Analysis of Aircraft and Satellite Measurements from the Intercontinental Chemical Transport Experiment (INTEX-B) to Quantify Long-Range Transport of East Asian Sulfur to Canada, Atmos. Chem. Phys., 8, 2999-3014, 2008. PDF

--Bob Y. 09:41, 23 February 2010 (EST)

Known issues

Large jump in emissions in Asia from 2005 to 2006

Jennifer Logan wrote:

I've inadvertently discovered what seems to be a problem with the time dependent emissions, that likely relates to when it switches from one base inventory to another. For CO, there is a huge difference between emissions in Asia for 2005 and 2006 - see Junhua's plots below:

• GEOS-4 vs GEOS-5 emissions comparison: SE Asia only
• GEOS-4 vs GEOS-5 emissions comparison: Larger region

I am guessing that this is because 2005 is scaled forward from the Streets inventory for 2000 (his latest for China I hope, not the original TRACE-P one), while 2006 is taken from the new Streets inventory for INTEX-B.

Jennifer