INTRODUCTION
Partly inspired by AMIP, the Paleoclimate Modeling Intercomparison Project
(PMIP) was initiated in order to coordinate and encourage the systematic
study of atmospheric general circulation models (AGCMs) and to assess their
ability to simulate large changes of climate such as those that occurred
in the distant past. Project goals include identifying common responses
of AGCMs to imposed paleoclimate "boundary conditions," understanding the
differences in model responses, comparing model results with paleoclimate
data, and providing AGCM results for use in helping in the analysis and
interpretation of paleoclimate data. PMIP is initially focussing on the
mid-Holocene (6,000 years Before Present) and the last glacial maximum
(21,000 yr BP) because climatic conditions were remarkably different at
those times and because relatively large amounts of paleoclimate data exist
for these periods. The major "forcing" factors are also relatively well
known at these times. Some of the paleoclimate features simulated by models
in previous studies seem consistent with paleoclimatic data, but others
do not. One of the goals of PMIP is to determine which results are model-dependent.
The PMIP experiments are limited to studying the equilibrium response of
the atmosphere (and such surface characteristics as snow cover) to changes
in boundary conditions (e.g., insolation, ice-sheet distribution, CO2 concentration,
etc.)
PMIP has been endorsed by both IGBP/PAGES and WCRP/WGNE, and eighteen
modeling groups are participating. Several of these groups have completed
one or more of the PMIP simulations. Model output will be archived at the
Program for Climate Model Diagnosis and Intercomparison (PCMDI) in a structure
similar to the AMIP standard output (abstract of Joussaume and Taylor 1995).
The present summary documentation of the PMIP models is inspired by
by the PCMDI Report No. 18, "A Summary Documentation of the AMIP Models"
by Thomas J. Phillips., in adapting it for PMIP versions of the models.
This summary documentation allows, as part of the subprojects, to facilitate the diagnostics and to focus on certain aspects of the simulations, in centralizing information on the main features of the models and summarizing the principal properties. Each description model contains the relevant references which allow to go further in the description of the algorithms and the parametrizations. At the beginning of the documentation are some tables that synthesize the most important informations about the PMIP simulations and a section describing the boundary conditions for the PMIP simulations. Then, the PMIP documentation follows the AMIP page set up in describing the main features for each PMIP model. Finally, the list of the references cited is found at the end of this documentation.