For barotropic (single-layer) flow, potential vorticity (ζ+f)/h is conserved following the motion, where h is the depth (vertical extent) of the air column. As a column of air moves over topography, its depth changes (compressed over high terrain, stretched over low terrain), forcing a corresponding change in absolute vorticity (ζ+f) to keep the ratio constant.
Initial state at 60°N: relative vorticity ζ=0, planetary vorticity f = 2Ω sin(60°) = 2 × 7.292×10⁻⁵ s⁻¹ × sin(60°) = 1.4584×10⁻⁴ × 0.8660 ≈...
Full option-by-option analysis available to enrolled students.