Environmental Engineering Reference
In-Depth Information
low-pressure trough. The wind suddenly veers as the wave passes, to be followed fairly
quickly by the clearance of the cloud and a return to undisturbed trade wind flow.
The passage of the wave is not dramatic, therefore, but in areas where the weather
hardly changes it does at
Figure 7.13
Easterly waves: (a) surface pressure, (b) 500
hPa streamline flow and (c) vertical cross-section.
least provide a little variety. Moreover, in areas such as the Caribbean, where the waves
are frequent, they are responsible for a significant proportion of the annual precipitation.
TROPICAL CYCLONES
Throughout much of the tropics one of the other main features of the weather is the
tropical cyclone (Plate 7.5). Unlike its counterparts in middle latitudes, this system is not
large; instead it consists of a small, intense, revolving storm with cloud bands spiralling
away from its centre, usually containing heavy squalls of rain, thunderstorms and even
