AR4 Coupled Climate System Models for late 19th and 20th Century Diagnostics

GISS ModelE

GFDL

CCSM3

Atmosphere (horizontal resolution, #levels)

4x5, 20L, model top 0.1mb

2x2.5, 24L

CAM3, T85, 26L

Ocean (horizontal resolution, #levels)

Russell et al (2000), HYCOM (Sun and Hansen, 2003), synchronous coupling

1 degree, 1/3 deg. Eq. Tropics (based on MOM4); 50L, GM, KPP

POP, 1deg(1/2 deg Eq. Tropics), 40L, GM, KPP

Temporal Resolution

Monthly means for all quantities. higher resolution
data for selected quantities may be available

Monthly averages available throughout the runs; Daily data will be available for a relatively small subset of variables
throughout the runs.

Monthly averages for all time periods, and daily data for sub-periods:
1961-2000, 2046-2065, 2081-2100, 2146-2165, 2181-2200, 2246-2265 and 2281-2300
Some 3 hourly data from single years : 2000, 2050, 2100, 2150, 2200, 2250 and 2300
Full descriptions are listed at:
http://www-pcmdi.llnl.gov/cmip/standard_output.html

Sea Ice Model

Russell et al. 2000 and Schmidt et al 2004

Winton (2000) for thermodynamics, Hunke and Dukowicz (1997) for dynamics, Briegleb et al (2002) for albedo dependence

CSIM4 (EVP dynamic and thermodynamic)

Land Surface

Rosenzweig and Abramopoulos (1997) with modifications described in Friend and Kiang (2004)

Land Dynamics Model based on Milly and Shmakin (2002); vegetation cover type varies from 1860 to 2000

CLM

Flux Adjustment

None

Sulfates

sulfate forcings (yes)

Non-volcanic sulfate aerosol (1860-2000) is derived from MOZART-2 model. Emissions vary by decade.

Direct effect from sulfur cycle model using time and space-varying SO2 emissions (Smith et al. 2001)

Solar

1366.3 solar constant (variable over time according to Lean (2000)

Time varying solar from Lean (2000)

Lean et al. 1995

Volcanoes

Volcanic forcing (yes)

1860-2000 volcanic aerosol forcing from Stenchikov (personal communication), based on Sato et al. (1993), Haansen et al. (2002), and Stenchikov et al (1998).

Ammann et al. 2003

Ozone

trop and strat 03

Tropospheric ozone (1860-2000) is derived from MOZART-2 model (Horowitz et al, 2003) with time and space-varying emissions. Emissions vary by decade. Stratospheric ozone (1979-2000) follows analyses by Randel (personal communication), based on monthly mean, zonal-mean observations. Strat ozone prior to 1979 uses the approximate 1979 data. Strat, trop ozone data are merged smoothly.

20th century tropospheric ozone spatially varying from MOZART model, and zonal mean stratospheric ozone (Kiehl et al., 1999); after 2000, tropospheric 3D monthly patterns for year t same as year 2000 patterns but scaled by Q(t)/Q(2000) where Q = global mean radiative forcing from Wigley et al. (2002); stratospheric ozone recovers consistent with Montreal Protocol

GHGs

well mixed GHGs

CO2,CH4,N2O, plus four halocarbons

(CO2, CH4, N2O) : IPCC TAR (ISAM for CO2)
Halocarbons (including SF6) : (Dai et al., 2001)

Other Aerosols

nitrates,carbonaceous aerosols, strat water vapor, land use(crops)

Black carbon, organic carbon, mineral dust, sea salt

carbon (population scaling), sea salt and dust (year 2000 values)

Anticipated Date of Data Availability

September 2004

Further Information

http://www.giss.nasa.gov/tools/modelE/

http://www.gfdl.noaa.gov/research/climate/ipcc_ar4.html

http://www.ccsm.ucar.edu/index.html

Reference paper(s) for the model

Schmidt et al, Hansen et al (in preparation)

In preparation