The Eta Model: Design, Use, and Added Value

Abstract

The design of the Eta model goes back to early ????s, when its original dynamical core was designed following the philosophy of “kio “rakawa of emulating important properties of the atmospheric governing equations. The core’s later major features were invented and implemented in the mid-????s. Once a comprehensive physics package was added, the model became operational as a regional NWP model in the United States in ????. Its use for regional climate projections followed later, for the South “merican region and then for a regional reanalysis over the North “merican region. Summary of the model’s dynamical core is given, followed by that of its physics package. Results of experiments revealing the model’s ability to generate added value even at large scales when run as a regional climate model ?RCM? are summarized. The Eta model is applied on various climate scales seamlessly, from subseasonal, seasonal to multidecadal, from coarse ?? km up to high ? km resolution. Examples of applications to various socioe‐ conomic sectors, such as for hydropower management, crop yield forecasts, environ‐ mental and forest conservation, urban areas management, assessment of natural disaster risks, etc., are given. The Eta RCM capability to reproduce extreme climatic values is pointed out.