QG vorticity scale: ζ_QG/f ≈ Ro

Quasi-geostrophic (QG) scaling: the relative vorticity ζ of a QG-approximated flow scales as ζ ≈ f·Ro, so the dimensionless ratio ζ/f ≈ Ro throughout the QG regime. This is the defining scaling relation of quasi-geostrophic theory — at…