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The 3D Quasi-Geostrophic system is a set of equations used inÌýmeteorology to describe the evolution of the atmosphere. The surfaceÌýquasi-geostrophic equation (2D SQG) is a well-studied special case whereÌýthe atmosphere above the earth is at rest. In this talk, we will discussÌýsome recent results.Ìý The first two deriveÌýboundary conditions for the 3D QG posed in a cylinder and constructÌýglobal in time weak solutions and local-in-time classical solutions. TheÌýsecond result shows the non-uniqueness of weak solutions to the 3D modelÌývia a convex integration argument.