COLA Anomaly Coupled Model Dynamical model
Center for Ocean-Land-Atmosphere Studies
Calverton, Maryland, U.S.
This prediction system includes a global anomaly coupled general circulation model for atmosphere and ocean.
The model is discretized in the vertical on 18 unevenly spaced sigma layers. The dynamic core used is from the National Center for Atmospheric Research (NCAR) Community Climate Model version 3 (CCM3) which uses a spherical harmonic expansion in the horizontal, truncated at wavenumber 42. The parameterization of shortwave radiation is the Lacis and Hansen (1974) scheme updated by Davies (1982), and the parameterization of longwave radiation follows Harshvardhan et al. (1987). The deep convection is an implementation of the Relaxed Arakawa-Schubert scheme of Moorthi and Suarez (1992) described by DeWitt (1996), and shallow convection is the scheme of Tiedtke (1984). The convective cloud fraction follows the scheme used in the CCM (Kiehl et al., 1994; see DeWitt and Schneider, 2000 for additional details). There is a turbulent closure scheme for the subgrid scale exchange of heat, momentum, and moisture (Mellor and Yamada, 1982; level 2.0). There is also a parameterization of gravity wave drag (Kirtman et al., 1992). This model is described in detail in Schneider (2002). The ocean component of the coupled model is the Geophysical Fluid Dynamics Laboratory Modular Ocean Model version 3 (MOM3; Pacanowski and Griffies, 1998). Details of the anomaly coupling strategy and the model forecast skill for 1980-2000 is described in Kirtman (2003) and Kirtman et al. (2002).
Browse forecasts of this model, shown in recent quarterly issues of the Experimental Long-Lead Forecast Bulletin, issued by COLA.
Contact: Dr. Ben Kirtman: kirtman@cola.iges.org
References:
Davies, R., 1982: Documentation of the solar radiation parameterization in the GLAS climate model. NASA Tech. Memo. 83961, 57 pp.
DeWitt, D. G., 1996: The effect of the cumulus convection scheme on the climate of the COLA general circulation model. COLA Tech. Rep. 27, 43 pp.
DeWitt, D. G. and E. K. Schneider, 2000: The tropical ocean response to a change in solar forcing. J. Climate, 13, 1133-1149.
Harshvardhan, R. Davis, D. A. Randall, and T. G. Corsetti, 1987: A fast radiation parameterization for general circulation models. J. Geophys. Res., 92, 1009-1016.
Kiehl, J. T., J. J. Hack, and B. P. Briegleb, 1994: The simulated Earth radiation budget of the National Center for Atmospheric Research community climate model CCM2 and comparisons with the Earth Radiation Budget Experiment (ERBE). J. Geophys. Res., 99, 20815-20827.
Kirtman, B. P., 2003: The COLA anomaly coupled model: Ensemble ENSO prediction. Mon. Wea. Rev., 131, 2324-2341.
Kirtman, B. P., Y. Fan, and E. K. Schneider, 2002: The COLA global coupled and anomaly coupled ocean-atmosphere GCM. J. Climate, 15, 2301-2320.
Kirtman, B. P., A. Vernekar, D. DeWitt, and J. Zhou, 1992: Impact of orographic gravity wave drag on extended range forecasts with the COLA GCM. Atmosfera, 6, 3-24.
Mellor, G. L. and T. Yamada, 1982: Development of a turbulence closure model geophysical fluid problem. Rev. Geophys. Space Phys., 20, 851-875.
Moorthi, S., and M. J. Suarez, 1992: Relaxed Arakawa-Schubert: A parameterization of moist convection for general circulation models. Mon. Wea. Rev., 120, 978-1002.
Pacanowski, R. C., and S. M. Griffies, 1998: MOM 3.0 Manual, NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, USA 08542.