ABSTRACT
The difficulty implicit in dividing the spectrum of tropical weather systems into two groups, ‘linear’ and ‘non-linear’, is considerable indeed. R. M. Leigh and M. Cox and G. Jager have documented and explained occasional fascinating occurences in the western Pacific in which two mature cyclones developed simultaneously on either side of the Equator near the same meridian. These are similar to others noted earlier over the Indian Ocean. Hurricanes are of principal significance, however, in that they constitute the most destructive group of weather systems in the world. Hurricane circulations are less vigorous than those of mid-latitude tornadoes, but tornadoes are comparatively tiny, and blaze trails of destruction on average only a few hundred metres broad. The regional studies indicate that most hurricanes move poleward as they mature and dissipate. Hurricanes have been described as simple heat engines, but, as such, they are most inefficient.
