2D turbulence, inverse energy cascade, and the k⁻⁵/³ spectrum
Vorticity Field ω
Energy Spectrum E(k)
K41: E(k) ~ k⁻⁵/³ in inertial range. 2D turbulence: dual cascade — energy goes to large scales (inverse), enstrophy to small (forward). Forcing injects energy at intermediate k.