As a tropical cyclone approaches, the barometer falls, at first slowly and then more quickly until it reaches an alarmingly low level. The pressure gradient at sea level near the centre of a mature cyclone is very steep, as shown by closely spaced isobars on a weather chart (Fig. 5.1). It is the steepness of the pressure gradient that accounts for the high wind velocities. Low pressure also has an important influence on storm surge (Section 5.3). The minimum pressure attained is one of two main parameters used to indicate tropical cyclone intensity. The other parameter is wind strength, discussed in Section 5.2.
KeywordsTropical Cyclone Storm Surge Cyclone Track Surge Height Tropical Cyclone Intensity
Unable to display preview. Download preview PDF.