Parallel Climate Model (PCM) Output Data

The Parallel Climate Model (PCM) a joint effort to develop a DOE-sponsored
parallel climate model between Los Alamos National Laboratory (LANL), the Naval
Postgraduate School (NPG), the US Army Corps of Engineers' Cold Regions
Research and Engineering Lab (CRREL) and the National Center for Atmospheric
Research (NCAR). We have coupled the NCAR Community Climate Model version 3,
the LANL Parallel Ocean Program, and a sea ice model from the Naval
Postgraduate School together in a massively parallel computer environment. This
is Version 1 of the PCM (PCM1).

Based on the experience with the NCAR Climate System Model, in order to
minimize the initial drift of the coupled system, the ocean/ice can be spun-up
with forcing from previous CCM3 runs with prescribed ocean temperatures. This
has also been useful in demonstrating and improving the kind of adjustments
that occur in the ocean and ice due to coupling the CCM3, without having to run
the more expensive coupled system. The full system has been in full production
with several control experiments and many ensemble climate change simulations
in progress and completed.

The PCM consists of 3 components:
Atmospheric Component
Ocean Component
Sea Ice Component
River Transport Component

The atmospheric component is the massively parallel version of the NCAR
Community Climate Model version 3.2 (CCM3). This model includes the latest
versions of radiation, boundary physics, and precipitation physics and is a
state-of-the-art atmospheric component. The CCM3 also includes the land surface
model (LSM) which takes into account soil physics and vegetation.

The ocean component is a limited spin-up of a moderate resolution global ocean
model with a
displaced pole grid using the POP (Parallel Ocean Program) model. The grid is
384 x 288 x 32, with an average resolution of 2/3 degree latitude and longitude
with increased latitudinal resolution near the equator of approximately 1/2
degree.

The PCTM dynamic-thermodynamic sea ice model has been developed by combining
two existing sea ice models from collaborating institutions: the ice dynamics
of the elastic-viscous-plastic model of Hunke and Dukowicz (Los Alamos CICE
model, 1997) with the thermodynamics and ice thickness distribution model from
the University of Washington (Bitz 2000; and Bitz and Lipscomb, 1999). The PCTM
ice model contains the same physics as the 2001 version of the NCAR CCSM sea
ice component, although the two models have different adaptations for
time-sequence in coupling to the other components and for separate execution on
parallel processors.

The river transport model (RTM) was developed by Marcia Branstetter and Jay
Famiglietti, researchers at the University of Texas, Austin, based on the work
of Vörösmarty et.al. (1989) and Miller et.al. (1994). This river routing scheme
uses the atmospheric T42 grid. The RTM takes into account river flow mass and
river direction in each watershed to pass water to the oceans.