Flow-following, finite-volume Icosahedral Model: Difference between revisions

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The '''Flow-following, finite-volume Icosahedral Model''' (FIM) is a [[numerical weather prediction]] model currently under development at the [[Earth SystemsSystem Research Laboratory]].

The FIM is intended to eventually supplant the [[Global Forecast System]], the United States's current medium-range forecast model, when operational (this was originally estimated to be some time around 2014). Its three-part name derives from its key features: "flow-following" indicates that its vertical coordinates follow [[isentrope]]s, and "finite-volume" describes the method used for calculating horizontal transport. The "icosahedral" portion describes the model's unique feature: whereas most grid-based forecast models have historically used rectangular grid points (a less than ideal arrangement for a planet that is a slightly [[oblate spheroid]], the FIM instead fits Earth to a [[truncated icosahedron]], with twelve evenly spaced pentagons (including two at the poles) anchoring a grid of hexagons.