Curvatures of measure-preserving diffeomorphism groups of non-orientable surfaces

Abstract We study curvatures of the groups of measure-preserving diffeomorphisms of non-orientable compact surfaces. For the cases of the Klein bottle and the real projective plane we compute curvatures, their asymptotics and the normalised Ricci curvatures in many directions. Extending the approach of Arnold and Lukatskii we provide estimates of weather unpredictability for natural models of trade wind currents on the Klein bottle and the projective plane.