Difference between revisions of "Sulfate aerosols"

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# Alkalinity computation for [[Sea salt aerosols]]
# Alkalinity computation for [[Sea salt aerosols]]
# Updates to regional and global [[Anthropogenic emissions|anthropogenic emissions inventories]]
# Updates to regional and global [[Anthropogenic emissions|anthropogenic emissions inventories]]
# Get liquid water content directly from GEOS-5 met fields for SO2 chemistry (in [[GEOS-Chem v8-03-02]])
# Get liquid water content and cloud fraction directly from GEOS-5 met fields for SO2 chemistry (in [[GEOS-Chem v8-03-02]])
# Other minor changes
# Other minor changes

Revision as of 14:00, 21 July 2010


Original formulation

From Park et al [2004]:

The sulfur simulation in GEOS-Chem is based on the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model [Chin et al., 2000a], with a number of modifications described below. Our fossil fuel and industrial emission inventory is for 1999-2000 and is obtained by scaling the gridded, seasonally resolved inventory from the Global Emissions Inventory Activity (GEIA) for 1985 [Benkovitz et al., 1996] with updated national emission inventories and fuel use data [Bey et al., 2001a]. The emissions for the United States and Canada are from U.S. EPA [2001], and the emissions for European countries are from European Monitoring and Evaluation Programme (EMEP)/United Nations Economic Commission for Europe (UNECE). Asian sulfur emission in the model is 20 Tg S yr1, which can be compared to year 2000 estimates of 17 Tg S yr1 by Streets et al. [2003] and 25 Tg S yr1 by Intergovernmental Panel on Climate Change (hereinafter IPCC) [2001]. Anthropogenic sulfur is emitted as SO2 except for a small fraction as sulfate (5% in Europe and 3% elsewhere) [Chin et al., 2000a].
Other anthropogenic sources of SO2 in the model include gridded monthly aircraft emissions (0.07 Tg S yr1) taken from Chin et al. [2000a] and biofuel use. We use a global biofuel CO emission inventory with 1° x 1° spatial resolution from Yevich and Logan [2003] and apply an emission factor of 0.0015 mol SO2 per mole CO [Andreae and Merlet, 2001]. Seasonal variations in biofuel emissions are specified from the heating degree days approach [Park et al., 2003].
Natural sources of sulfur in the model include DMS from oceanic phytoplankton and SO2 from volcanoes and biomass burning. The oceanic emission of DMS is calculated as the product of local seawater DMS concentration and sea-to-air transfer velocity. The seawater DMS concentrations are gridded monthly averages from Kettle et al. [1999], and the transfer velocity of DMS is computed using an empirical formula from Liss and Merlivat [1986] as a function of the surface (10 m) wind speed. The GEOS surface winds used here assimilate remote sensing data from the Special Sensor Microwave Imager instrument. Volcanic emissions of SO2 from continuously active volcanoes are included from the database of Andres and Kasgnoc [1998]. Emissions from sporadically erupting volcanoes show large year-to-year variability and are not included in the model. No major volcanic eruptions occurred in 2001. Biomass burning emissions of SO2 are calculated using a gridded monthly biomass burning inventory of CO constrained from satellite observations in 2001 by Duncan et al. [2003] with an emission factor of 0.0026 mol SO2 per mole CO [Andreae and Merlet, 2001].
The gas-phase sulfur oxidation chemistry in the model includes DMS oxidation by OH to form SO2 and MSA, DMS oxidation by nitrate radicals (NO3) to form SO2, and SO2 oxidation by OH to form sulfate. Reaction rates are from DeMore et al. [1997] and the yields of SO2 and MSA from DMS oxidation are from Chatfield and Crutzen [1990]. Aqueous-phase oxidation of SO2 by O3 and H2O2 in clouds to form sulfate is included using kinetic data from Jacob [1986] and assuming a pH of 4.5 for the oxidation by O3. Cloud liquid water content is not available in the GEOS data, and we specify it instead in each cloudy grid box by using a temperature-dependent parameterization [Somerville and Remer, 1984]. The cloud volume fraction in a given grid box is specified as an empirical function of the relative humidity following Sundqvist et al. [1989].
Ammonia emissions in the model are based on annual data for 1990 from the 1° x 1° GEIA inventory of Bouwman et al. [1997]
Production of total inorganic nitrate (gas-phase nitric acid and aerosol nitrate) in the model is computed from the ozone-NOx-hydrocarbon chemical mechanism.


Notable additions since Park et al [2004]:

  1. The GFED2 biomass burning inventory can now be used to compute biomass emissions of SO2 and NH3.
  2. Incorporation of new Volcanic SO2 emissions from Aerocom
  3. Alkalinity computation for Sea salt aerosols
  4. Updates to regional and global anthropogenic emissions inventories
  5. Get liquid water content and cloud fraction directly from GEOS-5 met fields for SO2 chemistry (in GEOS-Chem v8-03-02)
  6. Other minor changes

--Bob Y. 11:13, 13 July 2010 (EDT)

Source code and data

The source code for reading in the anthropogenic and aircraft emissions is contained sulfate_mod.f.

Emissions inventories include:

  1. DMS seawater concentrations [nm/ML] from Andreae
  2. NH3 anthropogenic emissions for year 1990 [kg N/month] from GEIA
  3. NH3 biofuel emissions for year 1990 [kg NH3/month] from GEIA
  4. NH3 natural-source emissions for year 1990 [kg N/month] from GEIA
  5. SO2 emissions from aircraft [kg/day] from Chin et al [2000].
  6. Various ship emissions inventories
  7. Volcanic emissions of SO2

For more information about the sulfate emissions 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. 14:31, 12 March 2010 (EST)


  1. Andreae, M. O., and P. Merlet (2001), Emission of trace gases and aerosols from biomass burning, Global Biogeochem. Cycles, 15(4), 95596
  2. Andres, R. J., and A. D. Kasgnoc, A time-averaged inventory of subaerial volcanic sulfur emissions, J. Geophys. Res., 103(D19), 25,251-25,261, 1998.
  3. Benkovitz, C. M., M. T. Scholtz, J. Pacyna, L. Tarrason, J. Dignon, E. C. Voldner, P. A. Spiro, J. A. Logan, and T. E. Graedel, Global gridded inventories of anthropogenic emissions of sulfur and nitrogen, J. Geophys. Res., 101(D22), 29,239-29,253, 1996.
  4. Bey, I., D. J. Jacob, R. M. Yantosca, J. A. Logan, B. Field, A. M. Fiore, Q. Li, H. Liu, L. J. Mickley, and M. Schultz, Global modeling of tropospheric chemistry with assimilated meteorology: Model description and evaluation, J. Geophys. Res., 106, 23,073-23,096, 2001. PDF
  5. Bouwman, A. F., D. S. Lee, W. A. H. Asman, F. J. Dentener, K. W. VanderHoek, and J. G. J. Olivier, A global high-resolution emission inventory for ammonia, Global Biogeochem. Cycles, 11(4), 561-587, 1997.
  6. Chatfield, R. B., and P. J. Crutzen, Are there interactions of iodine and sulfur species in marine air photochemistry?, J. Geophys. Res., 95(D13), 22,319-22,341, 1990.
  7. DeMore, W. B., S. P. Sander, D. M. Golden, R. F. Hampson, M. J. Kurylo, C. J. Howard, A. R. Ravishankara, C. E. Kolb, and M. J. Molina, Chemical kinetics and photochemical data for use in stratospheric modeling, JPL Publ., 97-4, 1-278., 1997.
  8. Duncan, B. N., R. V. Martin, A. C. Staudt, R. Yevich, and J. A. Logan, Interannual and seasonal variability of biomass burning emissions constrained by satellite observations, J. Geophys. Res., 108(D2), 4100, doi:10.1029/2002JD002378, 2003. PDF
  9. Jacob, D. J., Chemistry of OH in remote clouds and its role in the production of formic acid and peroxymonosulfate,J. Geophys. Res., 91(D9), 9807-9826, 1986.
  10. Kettle, A. J., et al. A global database of sea surface dimethylsulfide (DMS) measurements and a procedure to predict sea surface DMS as a function of latitude, longitude, and month, Global Biogeochem. Cycles, 13(2), 399-444., 1999.
  11. Liss, P. S., and L. Merlivat (1986), Air-sea gas exchange rates: Introduction and synthesis, in The Role of Air-Sea Exchange in Geochemical Cycling, edited by P. Buat-Me´nard, pp. 113-127, D. Reidel, Norwell, Mass, 1986.
  12. 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
  13. Yevich, R., and J. A. Logan, An assessment of biofuel use and burning of agricultural waste in the developing world, Global Biogeochem. Cycles, 17(4), 1095, doi:10.1029/2002GB001952, 2003. PDF
  14. Somerville, R. C. J., and L. A. Remer, Cloud optical thickness feedbacks in the CO2 climate problem, J. Geophys. Res., 89(D6), 9668-9672, 1984.
  15. Streets, D. G., et al. An inventory of gaseous and primary aerosol emissions in Asia in the year 2000, J. Geophys. Res., 108(D21), 8809, doi:10.1029/2002JD003093, 2003.

--Bob Y. 14:36, 23 February 2010 (EST)

Known issues

Updated THNO3.geos4.4x5 file

Lyatt Jaegle wrote:

I was trying to run GEOS-Chem (v8-01-03) in the offline aerosol mode with GEOS-4 met fields and ran into a problem: it seems that the offline file GEOS_4x5/sulfate_sim_200508/offline/THNO3.geos4.4x5 is in units of ppbv instead of v/v as expected in routine GET_HNO3_UGM3. This leads to issues in RPMARES which thinks that HNO3 is very large. I checked all the other files, and they are in v/v, as expected.

Bob Yantosca wrote:

Thanks Lyatt. I've downloaded the file and updated the README in the GEOS_4x5/sulfate_sim_200508/offline directory.

--Bob Y. 14:19, 24 April 2009 (EDT)

Fix for mass balance of HNO3 and NIT

Becky Alexander wrote:

We need to make a change in sulfate_mod in order to have mass balance for HNO3 and NIT. Duncan Fairlie noticed the bug. There is a simple change:
In routine SEASALT_CHEM in sulfate_mod.f: In order to have mass balance, you need to change:
   !HNO3 lost [eq/timestep] converted back to [v/v/timestep]
   HNO3_ss = TITR_HNO3 * 0.063 * TCVV(IDTHNO3)/AD(I,J,L)
   !HNO3 lost [eq/timestep] converted back to [v/v/timestep]
   HNO3_ss = HNO3_SSC * 0.063 * TCVV(IDTHNO3)/AD(I,J,L)
In my original code where I added isorropia and the new tracers, NITs and SO4s, the line above:
   !HNO3 lost [eq/timestep] converted back to [v/v/timestep]
   HNO3_ss = TITR_HNO3 * 0.063 * TCVV(IDTHNO3)/AD(I,J,L)
is appropriate as long as you also have PNIT (analogous to PNITs). PNIT is in my original code where I did all my mass balance testing. PNIT got dropped when going to the standard version. I don't recall dropping this, but my guess is that I decided it was redundant to have it when isorropia would just repartition HNO3 and NIT anyway according to thermodynamic equilibrium. But when dropping PNIT, you have to change TITR_HNO3 to HNO3_SSC in the above equation in order to achieve mass balance.

NOTE: This fix is was standardized in GEOS-Chem v8-01-02.

--Bob Y. 16:36, 19 February 2010 (EST)