Forcings in GISS Climate Model

Tropospheric Aerosols

Tropospheric aerosol optical thickness and single scattering albedo are time and space dependent and need to be calculated within a full climate model, driven by changes in emissions and other climate forcings. Aerosol types since the SI2002 model have included sea salt, dust, sulphates, organic and black carbon. In CMIP5, we additionally included nitrates. The anthropogenic aerosols (sulfate, nitrate, industrial black carbon and industrial organic carbon) have time dependent emissions, while emissions of the natural components are interactive with climate simulation (for instance, depending on wind speed for dust and sea salt).

CMIP5 Simulations

Transient aerosol treatment in the CMIP5 Historical simulations was described in Miller et al. (2014).

Fig 5 from Miller et al (2014)

Figure: Aerosol radiative forcing (W/m2) in the GISS E2-R NINT and TCADI ensembles (1850 to 2000). (a and b) direct radiative forcing, (c and d) indirect effect, (e and f) total aerosol forcing. For the TCADI ensemble, the total aerosol forcing is taken from the effective radiative forcing (ERF) (Shindell et al., 2013), and the indirect effect is diagnosed by subtracting the direct radiative forcing from the ERF.

Aerosol diagnostics in the TCADI (Interactive) simulations are available from the CMIP5 archive, while the inputs for the NINT (non-interactive) simulations which were taken from Koch et al. (2011) are available here.

Mineral dust aerosols were based on Cakmur et al. (2006) with updated tunings as described in Miller et al. (2014). The dust concentrations in the non-interactive simulations are available here, and the diagnosed concentrations for dust in the interactive runs is available as a diagnostic from the CMIP5 archive.

Three-dimensional aerosol mass amounts in the CMIP5 NINT simulations are available for download (netCDF files):

CMIP3 Simulations

The values for 1850, 1950 and 1990 are shown in the following figure. The 1850 to 1990 and 1950 to 1990 changes in the optical thickness are shown in the bottom panel.

Global maps of optical thickness and single scattering albedo

Maps of change of optical thickness

The sources for most of the aerosol data are discussed by Tegen et al. (2000) and Koch (2001). Industrial black carbon (BC) distributions were calculated at 10 year intervals using the GISS tracer transport model using the method described by Cooke and Wilson (1996) to derive BC emissions from a United Nations energy statistics data base. BC from biomass burning and natural organic carbon (OC) are from Liousse et al. (1996). Industrial OC emissions are assumed to be four times those of industrial BC, following Liousse et al. (1996). Soil dust is based on Tegen and Fung (1995) and Tegen and Lacis (1996). The sea salt distribution is based on Tegen et al. (1997), but the optical depths have been multiplied by four as suggested by Quinn and Coffman (1999) and Haywood et al. (1999).

Tropospheric Aerosol Optical Thickness and Single Scattering Albedo for SI2002 and SI2004 Models
Optical Thickness × 100 Single Scattering Albedo
SI2002 SI2004 SI2002 SI2004
1880 1990 1880 1990 1880 1990 1880 1990
Tropospheric Sulfate
  natural 0.40 0.40 0.67 0.67 1.00
  biomass burning 0.06 0.06 0.05 0.10 1.00
  industrial 0.14 1.82 0.20 3.03 1.00
Black Carbon
  natural 0.00 0.00 0.00 0.00 x
  biomass burning 0.13 0.13 0.25 0.50 0.30
  industrial 0.02 0.14 0.04 0.49 0.30
Organic Carbon
  natural 0.09 0.09 0.15 0.15 0.97
  biomass burning 0.96 0.96 0.77 1.54 0.97
  industrial 0.16 0.54 0.26 0.77 0.97
Nitrate 0.00 0.00 0.28 1.00 1.00
Soil Dust 3.24 3.24 3.24 3.24 0.89
Sea Salt 3.60 3.60 3.55 3.55 1.00
Total 8.8 11.0 9.5 15.0 0.953 0.956 ? ?

The geographic distributions of these aerosols are shown in the maps below. (Some corrections were made by A. Lacis in September 2003.), The maps figure is also available as a PDF.

Maps of annual mean optical thickness for different aerosol type

We have data for the geographic distributions of the aerosols at 1875, 1900, 1925, 1950, 1960, 1970, 1980 and 1990. Assuming there was no industrial aerosols in 1850, we interpolate between the data linearly for 1850 to 1950, and for 1950 to 1990 interpolate between the data using the annual emissions data as shown in parts (a) and (b) of the figure below, where the sulfate curve is applied to anthropogenic sulfate and the BC curve is used for industrial BC and industrial OC. And after 1990 the aerosols are assumed to be constant.

Line graphs over time of asrosol emissions>

Color version of "Figure 3. Estimated fossil-fuel BC emissions" from Novakov et al. (2003); also available as a PDF.

Line graphs of estimated fossil-fuel BC emissions from Novakov et al. (2003)

The global-mean changes in optical thickness and forcing is given in the graphs below.

Line graphs of optical thicknesses and mean forcings

The geographic distributions for the forcing is shown in the maps below.

Global maps of annual mean forcings due to aerosol change

Download forcing data:

Download additional data:

Click for D. Koch's three-dimensional aerosol mass data.

Additional information is available on the soil dust aerosols datasets page.

Related figures (PDF) from Sato et al. (2003):


Please address scientific inquiries about these data to Dr. Susanne Bauer.


Cakmur, R.V., R.L. Miller, J.P. Perlwitz, I.V. Geogdzhayev, P. Ginoux, D. Koch, K.E. Kohfeld, I. Tegen, and C.S. Zender, 2006: Constraining the global dust emission and load by minimizing the difference between the model and observations. J. Geophys. Res., 111, D06207, doi:10.1029/2005JD005791.

Cooke, W.F. and J.N. Wilson, 1996: A global black carbon aerosol model, J. Geophys. Res. 101, 19395-19409.

Haywood, J.M., V. Ramaswamy and B.J. Soden, 1999: Tropospheric aerosol forcing in clear-sky satellite observations over the oceans, Science 283, 1299-1303.

Koch, D., D. Jacob, I. Tegen, D. Rind and M. Chin, 1999: Tropospheric sulfur simulation and sulfate direct radiative forcing in the Goddard Institute for Space Studies general circulation model. J. Geophys. Res. 104, 23799-23822.

Koch, D., 2001: Transport and direct radiative forcing of carbonaceous and sulfate aerosols in the GISS GCM. J. Geophys. Res. 106, 20311-20332, doi:10.1029/2001JD900038.

Koch, D., S. Bauer, A. Del Genio, G. Faluvegi, J.R. McConnell, S. Menon, R.L. Miller, D. Rind, R. Ruedy, G.A. Schmidt, and D. Shindell, 2011: Coupled aerosol-chemistry-climate twentieth century transient model investigation: Trends in short-lived species and climate responses. J. Climate, 24, 2693-2714, doi:10.1175/2011JCLI3582.1.

Lefohn, A.S., J.D. Husar and R.B. Husar, 1999: Estimating historical anthropogenic global sulfur emission patterns for the period 1850-1990, Atmos. Environ. 33, 3435-3444.

Liousse, C. J.E. Penner, C. Chuang, J.J. Walton, H. Eddleman and H. Cachier, 1996: A global three-dimensional model study of carbonaceous aerosols, J. Geophys. Res. 101, 19411-19432.

Mao, J. and A. Robock, 1998: Surface air temperature simulated by AMIP general circulation models: volcanic and ENSO signals and systematic errors, J. Climate 11, 1538-1552.

Miller, R.L., G.A. Schmidt, L.S. Nazarenko et al., 2014: CMIP5 historical simulations (1850-2012) with GISS ModelE2. J. Adv. Model. Earth Syst., 6, no. 2, 441-477, doi:10.1002/2013MS000266.

Novakov, T., V. Ramanathan, J.E. Hansen, et al., 2003: Large historical changes of fossil-fuel black carbon aerosols, Geophys. Res. Lett. 30, 6, 1324-1327, doi:10.1029/2002GL016345.

Quinn, P.K. and D.J. Coffman, 1999: Comment on "Contribution of different aerosol species to the global aerosol extinction optical thickness: Estimates of model results" by Tegen et al., J. Geophys. Res. 104, 4241-4248.

Shindell, D.T., J.-F. Lamarque, M. Schulz, M. Flanner, C. Jiao, M. Chin, P.J. Young, Y.H. Lee, L. Rotstayn, N. Mahowald, G. Milly, G. Faluvegi, Y. Balkanski, W.J. Collins, A.J. Conley, S. Dalsoren, R. Easter, S. Ghan, L. Horowitz, X. Liu, G. Myhre, T. Nagashima, V. Naik, S.T. Rumbold, R. Skeie, K. Sudo, S. Szopa, T. Takemura, A. Voulgarakis, J.-H. Yoon, and F. Lo, 2013: Radiative forcing in the ACCMIP historical and future climate simulations. Atmos. Chem. Phys., 13, 2939-2974, doi:10.5194/acp-13-2939-2013.

Tegen, I. and I. Fung, 1995: Contribution to the mineral aerosol load from land surface modification. J. Geophys. Res. 100, 18707-18726, 1995.

Tegen, I. and A.A. Lacis, 1996: Modeling of particle size distribution and its influence on the radiative properties of mineral dust aerosol. J. Geophys. Res. 101, 19237-19244.

Tegen, I., P. Hollrigl, M. Chin, I. Fung, D. Jacob and J. Penner, 1997: Contribution of different aerosol species to the global aerosol extinction optical thickness: Estimates from model results. J. Geophys. Res. 102, 23895-23915.

Tegen, I., D. Koch, A.A. Lacis and M. Sato, 2000: Trends in tropospheric aerosol loads and corresponding impact on direct radiative forcing between 1950 and 1990: A model study. J. Geophys. Res. 105, 26971-26989.

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This page was written by Dr. Makiko Sato and Dr. Susanne Bauer.

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