Lawrence Livermore Laboratories
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The Livermore Atmospheric Model
(LAM)
In 1960, Cecil E. "Chuck" Leith began work on a GCM at Lawrence
Livermore National Laboratories. Trained as a physicist, Leith became
interested in atmospheric dynamics and received the blessing of LLNL
director Edward Teller for a project on the general circulation.
Teller's approval stemmed from his long-term interest in weather
modification.
After receiving encouragement from Jule Charney, Leith spent a summer
in Stockholm at the Swedish Institute of Meteorology. There he coded
a five-level GCM for LLNL's newest computer, the Livermore Automatic
Research Calculator (LARC), due to be delivered in the fall of 1960.
Leith wrote the code based on the manual for the new machine.
Although aware of the Smagorinsky/Manabe and Mintz/Arakawa efforts,
Leith worked primarily on his own. He had a working five-level model
by 1961. However, he did not publish his work until
1965.[1]
Nevertheless, by about 1963 Leith had made a film showing his model's
results in animated form and had given numerous talks about the
model.
Leith ceased work on his model -- known as LAM ("Leith Atmospheric
Model" or "Livermore Atmospheric Model") --in the mid-1960s, as he
became increasingly issued in statistical modeling of turbulence. In
1968, he went to the National Center for Atmospheric
Research.
LAM: Model Characteristics
The initial model was based on the
Bjerknes/Richardson primitive equations. It had five vertical levels
and used a 5° x 5° horizontal grid. It covered only the
northern hemisphere, with a "slippery wall" at 60°N. In order to
damp the effects of small-scale atmospheric waves, Leith introduced
an artificially high viscosity, which caused serious problems and
stimulated Leith's career-long interest in turbulence problems.
Back to GCM Family Tree
References
[1] C.E. Leith, "Numerical Simulation of the Earth's Atmosphere," in Methods in Computational Physics, eds. B. Alder, S. Fernbach, and M. Rotenberg (New York: Academic Press, 1965), 1-28.