Correspondence, speeches, presentations, writings, subject files, military records, printed matter, computer printouts, computer graphics, photographs, and other papers documenting Lorenz's career as a professor of meteorology at Massachusetts Institute of Technology and his discovery of deterministic chaos. Subjects include chaos theory, computer programming for weather and climate modeling, long-range weather prediction, and numerically based weather forecasting. Includes material pertaining to his service as a weather forecaster in the U.S. Army Air Forces. Correspondents include Hidetoshi Arakawa, Maurice L. Blackmon, William Blumen, Glenn W. Brier, E.V. Chelam, Richard A. Craig, D.A. Davies, Thomas Vivian Davies, John A. Dutton, Isadore Enger, John Firor, W. Lawrence Gates, Michael Ghil, James Gleick, F. Kenneth Hare, Isaac M. Held, Henry G. Houghton, Charles L. Jordan, Elizabeth A. Kelley, William H. Klein, E.B. Kraus, Cecil E. Leith, Gordon J. MacDonald, Thomas F. Malone, Yale Mintz, H. Stuart Muench, Jack Nord,̜ Jos ̌Pinto Peixoto, S.I. Rasool, Walter Orr Roberts, P.L. Schereschewsky, William D. Sellers, Bernard Shorr, J. Smagorinsky, Kenneth C. Spengler, Philip Duncan Thompson, Kevin E. Trenberth, and James A. Yorke.