  We consider a system describing the motion of an isentropic, inviscid, weakly
com-pressible, fast rotating fluid in the whole space R^3 , with initial data
belonging to H^s(R^3) , s \textgreater{} 5/2. We prove that the system admits a
unique local strong solution in L^$\infty$([0, T ]; H^s(R^3)) , where T is
independent of the Rossby and Mach numbers. Moreover, using Strichartz-type
estimates, we prove that the solution is almost global, i.e. its lifespan is of
the order of $\epsilon$^(--$\alpha$) , $\alpha$ \textgreater{} 0, without any
smallness assumption on the initial data (the initial data can even go to
infinity in some sense), provided that the rotation is fast enough.
