MASAGE NH3 inventory

Overview

MASAGE_NH3 is an inventory of agricultural NH3 emissions developed by Fabien Paulot. A full description is given in Paulot et al (2014).

From the abstract to Paulot et al (2014):

We use the adjoint of a global 3-D chemical transport model (GEOS-Chem) to optimize ammonia (NH3) emissions in the U.S., European Union, and China by inversion of 2005–2008 network data for NH₄⁺ wet deposition fluxes. Optimized emissions are derived on a 2° x 2.5° grid for individual months and years. Error characterization in the optimization includes model errors in precipitation. Annual optimized emissions are 2.8 Tg NH₃−N a⁻¹ for the contiguous U.S., 3.1 Tg NH₃−N a^-1 for the European Union, and 8.4 Tg NH₃−N a⁻¹ for China. Comparisons to previous inventories for the U.S. and European Union show consistency (∼ +/-15%) in annual totals but some large spatial and seasonal differences. We develop a new global bottom-up inventory of NH3 emissions (Magnitude And Seasonality of Agricultural Emissions model for NH₃ (MASAGE_NH3)) to interpret the results of the adjoint optimization. MASAGE_NH3 provides information on the magnitude and seasonality of NH3 emissions from individual crop and livestock sources on a 0.5° x 0.5° grid. We find that U.S. emissions peak in the spring in the Midwest due to corn fertilization and in the summer elsewhere due to manure. The seasonality of European emissions is more homogeneous with a well-defined maximum in spring associated with manure and mineral fertilizer application. There is some evidence for the effect of European regulations of NH3 emissions, notably a large fall decrease in northern Europe. Emissions in China peak in summer because of the summertime application of fertilizer for double cropping.

Reading MASAGE into GEOS-Chem

Data file

We have implemented the MASAGE NH3 inventory into GEOS-Chem via the HEMCO emissions component. We use the emissions file stored in the HEMCO data path:

HEMCO/MASAGE_NH3/v2015-02/masage_nh3_2006.2x25.nc

This data file contains monthly mean NH3 emissions for the various agricultural sectors mentioned in Paulot et al (2014). The emissions data are placed on the GEOS-Chem 2° x 2.5° horizontal grid, and the base year of emissions is 2006. Units of NH3 emissions are given as kg NH3 m^-2 s^-1.

Emission totals

If we convert the units of the data fields in file masage_nh3_2006.2x25.nc from kg NH3 m^-2 s^-1 to Gg N, we can directly compare with Table A1 of Paulot et al (2014). (The unit conversion involves multiplying each emissions field by the factor 14.0/17.0/1e6, and then summing over all 12 months). We then obtain the following global totals:

    EMISSION TOTALS, compare to the "World" column of Table A1 of Paulot et al (2014)
    COTTON               [kg N] 731.352
    FRUITS_VEGETABLES    [kg N] 820.576
    GROUNDNUT            [kg N] 80.8127
    MAIZE                [kg N] 1743.05
    OIL_PALM             [kg N] 112.432
    OTHER_CEREALS        [kg N] 122.545
    OTHER_CEREALS_WINTER [kg N] 336.14
    OTHER_CROPS          [kg N] 987.441
    PULSES               [kg N] 44.6072
    RAPESEED             [kg N] 155.898
    EARLY_RICE           [kg N] 554.186
    LATE_RICE            [kg N] 323.54
    SOYBEANS             [kg N] 85.5041
    SUGAR_CANE           [kg N] 428.529
    TEMPERATE_ROOTS      [kg N] 459.644
    TROPICAL_CEREALS     [kg N] 92.0221
    TROPICAL_ROOTS       [kg N] 160.903
    WHEAT                [kg N] 423.498
    WHEAT_WINTER         [kg N] 1606.97
    BEEF_CROP            [kg N] 1998.11
    BEEF_HOUSING         [kg N] 5900.38
    BEEF_PASTURE         [kg N] 1672.35
    BEEF_STORAGE         [kg N] 549.203
    BUFFALOES_EMISSION   [kg N] 1525.14
    DAIRY_CROP           [kg N] 685.603
    DAIRY_HOUSING        [kg N] 1112.69
    DAIRY_PASTURE        [kg N] 668.778
    DAIRY_STORAGE        [kg N] 811.267
    GOATS_EMISSION       [kg N] 690.562
    PORK_CROP            [kg N] 775.642
    PORK_HOUSING         [kg N] 2055.58
    PORK_PASTURE         [kg N] 608.831
    PORK_STORAGE         [kg N] 680.933
    POULTRY_CROP         [kg N] 928.715
    POULTRY_HOUSING      [kg N] 2186.11
    POULTRY_PASTURE      [kg N] 546.004
    POULTRY_STORAGE      [kg N] 323.869
    SHEEP_EMISSION       [kg N] 967.568

--Bob Y. 16:32, 5 February 2015 (EST)

References

1. Paulot F., Jacob, D.J., Pinder R.W., Bash J.O., Travis, K., Henze D.K., Ammonia emissions in the United States, Europe, and China derived by high-resolution inversion of ammonium wet deposition data: Interpretation with a new agricultural emissions inventory (MASAGE_NH3), J. Geophys. Res., 119, 4,343-4,364, 2014. PDF