ABSTRACT
The derivation of the long-wave equations is attributed to Carl Rossby, an outstanding meteorologist of the twentieth century. They afforded a breakthrough in thinking of meteorology after World War II. Such waves are often called Rossby waves. The theory developed here relies on the theorem of the conservation of absolute vorticity. The breakthrough in thinking came largely as a result of the invention of the radiosonde instrument which enabled temperatures and pressures to be measured in the upper atmosphere, and transmitted by radio to a ground-based receiver. In order to maintain a constant absolute vorticity trajectory the long wave must move in the opposite direction to that of the air current through the geostrophic control pattern. On the other hand, long-wave patterns move from east to west, upstream against the wind. Such movement is sometimes called retrogressive. These predicted motions are observed to be the case when we follow the movement of such waves on upper air weather charts.
