Eta Model is an atmospheric (meteorological forecasting) model developed in seventies and eighties years (by Mesinger & Janjic: Mesinger, F., and Z. I. Janjic, 1974: Noise due to time-dependent boundary conditions in limited area models. The GARP Programme on Numerical Experimentation, Rep. No. 4, WMO, Geneva, 31-32): the most recent version was written to use the eta vertical coordinate.
From 8 June 1993 is officially operational at NCEP and in many countries in its various versions.
The name of the model derives from the Greek letter Î· which denotes the vertical coordinate (Mesinger et al. 1988: Mesinger, F., Z. I. Janjic, S. Nickovic, D. Gavrilov, and D. G. Deaven, 1988. The step-mountain coordinate: model description and performance for cases of Alpine lee cyclogenesis and for a case of an Appalachian redevelopment. Mon. Wea. Rev., 116, 1493-1518. ).
Itâ€™s possible to find further general information about the model, documentation on model equations and model microphysics, and itâ€™s also possible to download an updated Fortran version which can run in UNIX or LINUX systems.