The Eta Model: Design, Use, and Added Value

Abstract

The design of the Eta model goes back to early 1970s, when its original dynamical core was designed following the philosophy of Akio Arakawa of emulating important properties of the atmospheric governing equations. The core's later major features were invented and implemented in the mid-1980s. Once a comprehensive physics package was added, the model became operational as a regional NWP model in the United States in 1993. Its use for regional climate projections followed later, for the South American region and then for a regional reanalysis over the North American 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 40 km up to high 5 km resolution. Examples of applications to various socioeconomic sectors, such as for hydropower management, crop yield forecasts, environmental 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.

Reducing Forecast Errors of a Regional Climate Model Using Adaptive Filters

“…The Eta model [5,6] has been employed by the Brazilian National Institute for Space Research (INPE) since 1996 [7] for high-resolution numerical weather forecasts. The Eta model employs as prognostic variables: air temperature, zonal and meridional wind components, specific humidity, surface pressure, turbulent kinetic energy, soil humidity and temperature, and liquid or ice water in clouds [8,9]. Climate forecasts using any numerical method/model (such as the Eta) will generally differ from the observed climatic conditions.…”

A Case Study of Anomalous Snowfall with an Alberta Clipper

“…For this case, analysis of synoptic-scale features was performed using the Eta model (Black [24]; Mesinger et al [25]), while the Rapid Update Cycle (RUC; Benjamin et al [26]) model was utilized to examine the UL jet streaks in finer detail, via both plan view and cross-section. The Eta model output was interpolated onto a horizontal grid with 80-km spacing and a 50-hPa vertical spacing, while the RUC model output was interpolated onto a similar grid with 25-hPa vertical intervals.…”

The study of the angular and spatial distribution of radio-selected AGNs and star-forming galaxies in the ELAIS N1 field

“…Constraint from Gunn Peterson trough in quasar absorption spectra indicate that the gas in the intergalactic medium (IGM) became completely ionized by redshift z ∼ 6 (Fan et al 2002;Fan, Carilli, & Keating 2006). The transition of the universe from the neutral to ionized phase is called the epoch of reionization (EoR) (Field 1958;Madau phd1601121009@iiti.ac.in 1997; Furlanetto, Oh, & Briggs 2006;Pritchard & Loeb 2012;Loeb & Furlanetto 2013;Mesinger 2016;Barkana 2016;Dayal & Ferrara 2018)). In the post reionization universe, several astrophysical parameters other than the gravitational clustering influenced the evolution of the baryonic matter density.…”