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.

It was possible effectively to do graphics to look at single images of isobars on the northern hemisphere polar projection, for example, of isopressure or cloud patterns--things of that sort. And by doing this sequentially, of course, one could generate motion pictures. This was, I think, one of the first of the evolving motion picture displays from a computer-generated atmospheric model. But I sympathized with them, because I noticed that when I was, in those years, talking about the behavior of the model to any audience, they didn't seem to care anything about the details of the model. They just wanted to see the movies!

But in the fall of 1960, we were getting the LARC computer, which was the first transistorized computer at the Livermore Laboratory. And it was thought that it would be about ten times faster than anything that we or others had. So I pointed out to the people I talked to that I didn't know very much about the atmosphere, but we were about to get a computer that was ten times faster--so didn't it make sense for me to try to build an atmospheric model on the UNIVAC 1, and what kind of contribution might that make? I was strongly encouraged to go ahead, to do that, and therefore I spent about a year or so before the delivery of the LARC in October 1960--getting ready for it. In fact, during the summer of 1960, I spent some months at the International Institute for Meteorology in Stockholm working on the development of this model code and having access to a library and people who had some familiarity with the nature of the problems encountered in doing this sort of thing.

In the fall, I returned to Livermore, the LARC was delivered, and I started running on it. In fact, I think I was running on it quite a bit sooner than almost anyone else, because I had spent this time getting ready for it.

Well, I became interested during the 1960s in the more fundamental aspect of the behavior of the atmosphere. That had to do with treating the large-scale motions of the atmosphere as a turbulent fluid, and trying to understand elements of the turbulence theory associated with this. Now, the turbulence theory involved in this case, because of the size of the global atmosphere and its thinness is more two-dimensional than it is three-dimensional. So this led to my becoming involved in what's called two-dimensional turbulence, which we discovered to have properties quite different than those of three-dimensional turbulence, and which served as kind of a prototype for the statistical behavior of the large-scale motions in the atmosphere. And so, much of my interest during the '60s was devoted to these issues of the nature of two-dimensional turbulence.

We equiped the LARC with a sprocketed film magizine that was fast and precise. This allowed the production of black and white movies. An early production code on the LARC computed a general circulation weather model. Movies of the weather model caused other weather modelers to acquire such equipment. Perhaps the emergent jet stream was first noticed in the calculation via these movies.

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.