F''-plane approximation

{
  "id": "MLC-T-MET-005744",
  "term": "F''-plane approximation",
  "field": "Meteorology and atmospheric science",
  "definition": "A higher-order simplification of the Coriolis parameter in which a Taylor expansion about a reference latitude is carried through the second derivative with respect to northward distance. Unlike the beta-plane approximation, which is linear, the resulting variation is quadratic, so it represents the curvature of the Coriolis parameter that the beta plane neglects. The constant-value f-plane approximation is the lowest-order form in this sequence.",
  "url": "https://mlchart.com/terminology/meteorology/f-plane-approximation/"
}