Part 6 — Turbulence & Circulation
From an unstable jet to the general circulation. Geostrophic turbulence cascades energy upscale into coherent vortices and, on a rotating planet, zonal jets; the same eddies set an effective diffusivity for any tracer they stir. Closes with the large-scale response to steady forcing: wind-driven gyres and their western boundary currents, and buoyancy-driven overturning circulation.