Question

13.
Hot air becomes less dense, expands and rises and cool air takes its place. State two
natural phenomena which occur based on this concept. Illustrate one of them with
appropriate labelling.

Answer 1

A few basic principles go a long way toward explaining how and why air moves: Warm air rising creates a low pressure zone at the ground. Air from the surrounding area is sucked into the space left by the rising air. Air flows horizontally at top of the troposphere; horizontal flow is called advection. The air cools until it descends. Where it reaches the ground, it creates a high pressure zone. Air flowing from areas of high pressure to low pressure creates winds. Warm air can hold more moisture than cold air. Air moving at the bases of the three major convection cells in each hemisphere north and south of the equator creates the global wind belts.

Air Pressure

Answer 2

Answer:

cool air compress each other

and hot air packed closely

so hot air less dense than cold air