Global Well-Posedness and Asymptotic Behavior for the 2D Subcritical Dissipative Quasi-Geostrophic Equation in Critical Fourier-Besov-Morrey Spaces

. In this paper, we study the subcritical dissipative quasi-geostrophic equation. By using the Littlewood Paley theory, Fourier analysis and standard techniques we prove that there exists v a unique global-in-time solution for small initial data be-longing to the critical Fourier-Besov-Morrey spaces FN 3 − 2 α + λ − 2 p p , λ , q . Moreover, we show the asymptotic behavior of the global solution v . i.e., k v ( t ) k FN 3 − 2 α + λ − 2 p p , λ , q decays to zero as time goes to inﬁnity.