Duba, C. T.Doyle, T. B.McKenzie, J. F.2014-08-112014-08-112014-03-31C.T. Duba, T.B. Doyle & J.F. McKenzie. 2014. Rossby wave patterns in zonal and meridional winds. Geophysical & Astrophysical Fluid Dynamics, 108 (3), 237-257, DOI: 10.1080/03091929.2013.867604http://hdl.handle.net/10321/1124The propagation properties of Rossby waves in zonal and meridional winds are analyzed using the local dispersion relation in its wave number form, the geometry of which plays a crucial role in illuminating radiation patterns and ray trajectories. In the presence of a wind/current, the classical Rossby wave number curve, an offset circle, is distorted by the Doppler shift in frequency and a new branch, consisting of a blocking line with an eastward facing indentation, arises from waves convected with or against the flow. The radiation patterns generated by a time harmonic compact source in the laboratory frame are calculated using the method of stationary phase and are illustrated through a series of figures given by the reciprocal polars to the various types of wave number curves. We believe these results are new. Some of these wave patterns are reminiscent of a “reversed” ship wave pattern in which cusps (caustics) arise from the points of inflection of the wave number curves; whilst others bear a resemblance to the parabolic like curves characteristic of the capillary wave pattern formed around an obstacle in a stream. The Rossby stationary wave in a westerly is similar to the gravity wave pattern in a wind, whereas its counterpart in a meridional wind exhibits caustics, again arising from points of inflection in the wavenumber curve.23 penRossby wavesβ-planeRadiation patternArticle