Bin Cheng visited the University of Reading on Tuesday 12 March and gave a talk in the Mathematics Seminar Series.  The title of the talk was “Analysis of some nonlinear PDEs from multi-scale geophysical applications” with abstract: the talk is about systems of PDEs from geophysical fluid dynamics with multiple time scales, in which linear skew-self-adjoint operators of size 1/epsilon give rise to highly oscillatory solutions.  Analysis is performed in justifying the limiting dynamics as epsilon goes to zero; furthermore, the analysis yields estimates on the difference between the multiscale solution and the limiting solution.  The talk will introduce a simple yet effective time-averaging technique which is especially useful in general domains where Fourier analysis is not applicable.