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[NOAA bullet] Is there a brief description available concerning the forcings implemented in the GFDL CM2.X Model climate of the 20th century experiments (1861-2000)?

Forcings implemented in the GFDL CM2.x Climate of the 20th Century Experiments (1861-2000)
[All values are monthly-means, then interpolated to yield a daily estimate in the model. Spatial distribution is the latitude-longitude grid of GFDL AM2 viz., 2 degrees x 2 degrees. Departures noted below. Wavelength-dependent properties implemented in the solar and longwave spectra].

  1. Well-mixed greenhouse gases (CO2, CH4, N2O, CFCs { F11, F12, F113, F22}) -----> SOURCE: IPCC (2001) and WMO (2003)
    [CO2 GRAPH]
    [CH4 GRAPH]
    [F11 GRAPH]
    [F12 GRAPH]
    [F113 GRAPH]
    [F22 GRAPH]
    [N2O GRAPH]
  2. Stratospheric Ozone (1977 to 2000 only) -----> SOURCE: Randel and Wu (1999). Zonal-means only.
  3. Tropospheric ozone -----> SOURCE: using MOZART chemistry-transport model-generated distributions {Horowitz et al., 2003; Tie et al., 2005}; "1990" climatology from NCAR's MACCM3 used for all years; emission values used are estimates at the beginning of each decade.
  4. All Tropospheric Aerosols: [Sulfate, Black and Organic Carbon]; [Dust and Sea-salt not assumed to vary - values held fixed at the 1990 estimates].
    Same methodology as for Tropospheric Ozone. SOURCE: black carbon and organic carbon from fossil-fuel sources {Cooke et al., 1999}; biomass burning from {Hao and Liu, 1994; Andrea and Merlet, 2001}. Historical emissions produced by scaling present-day values based on the EDGAR-HYDE historical emissions inventory {Van Ardenne et al., 2001}.
    Only sulfate aerosols are assumed to have a hygroscopic growth. External mixtures for radiation calculations.
  5. Tropospheric aerosol indirect forcing arising out of aerosol-cloud interactions -----> NOT INCLUDED.
  6. Land-use change SOURCE Hurtt et al. (2005) global land use reconstruction history, including effect on surface albedo, surface roughness, stomatal resistance, and effective water capacity.
  7. Solar irradiance variations -----> SOURCE {Lean et al., 1995; Lean, personal communication, 2003; see also IPCC, 2001}. Solar variations implemented as a function of wavelength.
    [SOLAR GRAPH]
  8. Volcanic aerosols -----> SOURCE: Ramachandran et al. (1999) Pinatubo estimates altered slightly and blended with Sato et al. (1993) estimates, then Sato et al. values used for eruptions going back to 1860.

  9. More details will be included in a manuscript that is being prepared. When the manuscript is submitted to a journal, it will be available for download from the CM2.x references web page.

Questions related to the GFDL CM2.x models may be directed to…


[email GFDL.Climate.Model.Info at noaa dot gov] 
last modified: November 13 2012.