Rossby waves occur in layers of fluid which are bounded by two planes almost perpendicular to an axis of rotation, but not quite parallel to each other. On Earth, Eric Weisstein's World of Astronomy they are easily observed in the meanders of the mid-latitude jet stream Eric Weisstein's World of Astronomy (Platzman 1968). Above the ocean, Rossby waves are harder to detect because they have amplitude 10 cm and wavelength 500 km (Chelton and Schlax 1996). Oceanic Rossby waves are driven by large-scale wind and buoyancy forcing at the eastern boundaries of continents and oceanic interiors.
References
Chelton, D. B. and Schlax, M. G. "Global Observations of Oceanic Rossby Waves." Science 272, 234-238, 1996.
Platzman, G. W. Q. J. R. Meteorol. Soc. 94, 225, 1968.
Rossby, C. G. et al. J. Mar. Res. 2, 38, 1939.
Rossby, C. G. Q. J. R. Meteorol. Soc. 66, 66, 1940.
