WVAntialiasing

Apply explicit spectral antialias filtering for diagnostics.

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Declaration

WVAntialiasing < WVForcing

Overview

This closure removes coefficient tendencies in aliased modes and sets those coefficients to zero after every integration step. The horizontal mask uses the transform’s quadratic-aliasing rule. Vertical modes with j >= Nj are discarded; Nj defaults to floor(2*wvt.Nj/3).

Transform-level antialiasing is enabled by default and is more efficient because discarded modes are never computed. Explicit antialiasing is intended for measuring the filter’s effect on energy and potential enstrophy. Construct the transform with shouldAntialias=false before adding this closure. It is compatible with wave-bearing and QG transforms.

Example

wvt = WVTransformConstantStratification([40e3,30e3,2e3],[8,6,5],N0=5.2e-3,latitude=45,isHydrostatic=true,shouldAntialias=false);
wvt.addForcing(WVAntialiasing(wvt));

Topics

• Create the forcing
  • WVAntialiasing Create explicit antialias filtering for a transform.
• Inspect forcing configuration
  • Nj Number of retained vertical modes.
• Inspect forcing or damping scales
  • effectiveHorizontalGridResolution Return the shortest fully retained horizontal wavelength.
  • effectiveJMax Return the highest retained vertical-mode number.

Developer Topics

These items document internal implementation details and are not part of the primary public API.

• Forcing persistence
  • classRequiredPropertyNames Returns the required property names for the class
• Forcing internals
  • M Logical-shape spectral mask of discarded coefficients.

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