Tropical cyclones are closed low - pressure system, generally about 650 km in diameter, which bring violent winds, torrential rainfall and thunderstorms. Generally, they contain a central region, the eye, with a diameter of about ten kilometres with light winds and more or less lightly clouded sky.
In order for cyclones to develop various conditions need to be fulfilled. There must be a plentiful supply of moisture, and for this reason distribution of cyclones is closely related to those regions where the highest sea - surface temperatures are found i.e. the western portion of the tropical oceans in late summer with temperature of at least 27°C. This moisture provides the necessary latent heat to drive the storm and to provide the rainfall.
Tropical cyclones tend to occur mainly in between the Tropic of Capricorn and Tropic of cancer except the equatorial region i.e. 5° on both sides of the equator because closer than that to the Equator the Coriolis parameter approaches Zero. The main cyclone activity in the Northern Hemisphere is in late summer and autumn during the time of the equatorial trough's northern displacement.
Which one of the following elements is not associated with tropical cyclones?
Correct Answer: (d) Dense fog
Solution:Dense fog is absent in tropical cyclones because it generated due to convergence of two different air masses like as in Temperate cyclones which is absent in tropical cyclone.