In this section, some 30 properties are described for each AMIP model. The
level of detail of the information is intermediate between that of an outline
and a comprehensive documentation of model features. Thus, the intent is to
qualitatively summarize the essence of the principal features of a model,
rather than to fully elaborate the quantitative details of the algorithms and
parameterizations. The latter may be found by examining the documentation cited in the feature descriptions (see the references within each model description, or the
comprehensive bibliography.
The AMIP representatives also may be consulted for details on model
parameterizations, boundary and initial conditions, and computational issues.
A strength of this summary documentation is that the features of the AMIP
models are elaborated with respect to a common set of categories. These are:
- AMIP representative(s)
- Model designation (following the WGNE-recommended form: Institution, Model Version (Horizontal/Vertical Resolution) "Vintage Year"
- Model lineage (predecessor and related models)
- Model documentation (key references)
- Horizontal representation (spectral or finite differences)
- Horizontal resolution
- Vertical domain (lowest/highest atmospheric levels)
- Vertical representation (coordinates and differencing schemes)
- Vertical resolution
- Computer/operating system (for the AMIP simulation)
- Computational performance (minutes per simulated day)
- Initialization (of atmospheric state, snow cover/depth, and soil moisture)
- Time integration scheme(s)
- Smoothing/filling (types of algorithms used)
- Sampling frequency (AMIP history storage interval)
- Atmospheric dynamics (state variables)
- Diffusion (horizontal and vertical)
- Gravity-wave drag
- Solar constant/cycles (AMIP solar constant, inclusion of diurnal cycle)
- Chemistry (radiatively active gases and aerosols)
- Radiation (shortwave/longwave schemes, cloud-radiative interactions)
- Convection (deep and shallow)
- Cloud formation (prognostic or diagnostic schemes)
- Precipitation (formation and subsequent evaporation)
- Planetary boundary layer (representation and depth)
- Orography (datasets, smoothing procedures)
- Ocean (treatment for AMIP simulation)
- Sea ice (treatment for AMIP simulation)
- Snow cover (formation/melting, effects on surface characteristics)
- Surface characteristics (surface types, roughness, albedo, emissivity)
- Surface fluxes (momentum, heat, and moisture)
- Land surface processes (vegetation and soil
thermodynamics/hydrology)
Although not an exhaustive accounting of model
features, these categories provide a framework for a reasonably comprehensive
description of the numerics, dynamics, and physics of the AMIP models. It is
acknowledged, however, that such a schema may convey the false impression that
model features which are nonlinearly interconnected are to be viewed as
independent entities. In a given feature summary, therefore, the
interdependence of model properties is made explicit by directing the reader to
examine the descriptions of related features (e.g., by referring to the
description of cloud formation in the summary of atmospheric radiation,
etc.). Hypertext links are provided to facilitate this cross referencing.
The model feature summary reports follow in the alphabetical order of the AMIP group acronyms.
Last update April 8, 1998. For further information, contact Tom Phillips (
phillips@tworks.llnl.gov)LLNL Disclaimers
UCRL-ID-116384
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