Page 2 - 2. Lesson notes- Air, Rain and Air pollution

• The atmosphere keeps the average temperature of the Earth fairly steady during the day

and even during the course of the whole year.
Movement of Air / winds:

• Winds are caused due to uneven heating of atmosphere.

• During day time, the air above the land gets heated faster and starts rising.

So air from above the sea comes to the low pressure region over land.
• At night both land and sea start to cool. Since water cools and land cools down at night

the descending air creates sea breeze.

The movement of air across the earth determines the weather and climate of all regions.
The sun’s radiation heats up the land, sea and the air.

Here, hot air increases and creates a low pressure over that area and cold air sinks and creates
a region of high pressure.

RAIN
Rain is droplets of water that are condensed as a result of evaporation that takes place during

the water cycle which causes the formation of clouds. Hence, rains occur due to the formation
of clouds. The process of rainfall can be explained by formation of cloud and water cycle.