In this article we apply the technique proposed in Deng-Hou-Yu (Comm. PDE, 2005) to study the level set dynamics of the 2D quasi-geostrophic equation. Under certain assumptions on the local geometric regularity of the level sets of $θ$, we obtain global regularity results with improved growth estimate on $| ∇^\bot θ |$. We further perform numerical simulations to study the local geometric properties of the level sets near the region of maximum $| ∇^\bot θ |$. The numerical results indicate that the assumptions on the local geometric regularity of the level sets of $θ$ in our theorems are satisfied. Therefore these theorems provide a good explanation of the double exponential growth of $| ∇^\bot θ |$ observed in this and past numerical simulations.