Long-Time Decay to the Global Solution of the 2D Dissipative Quasigeostrophic Equation
We study the behavior at infinity in time of any global solution θ in C (R , H^{ 2−2α} R^2) of the
surface quasigeostrophic equation with subcritical exponent 2/3 ≤ α ≤ 1. We prove that
the limit of θ is 0 in the space H^{ 2−2α} R^2. Moreover, we prove also the nonhomogeneous version of the previous result, and we prove that if θ ∈ C( R , H^{2−2α} R^2) is a global solution, then the limit is also 0.