Air for regulating temperatures or climate control
- The air moderates the temperature on earth for life to exist.
- Without the atmosphere, the daytime temperatures on earth would be as very high and at night it would be as cold as -30⁰ C which would make it very difficult for life to survive.
- The density of air reduces on heating and it rises upwards.
- Similarly, cold air is denser than the hot air which sinks towards the ground.
- As the hot air rises, it creates a space of low pressure where the cold air rushes in and occupies this space. This results in the movement of air called wind.
- As the hot region heats up the air and gets raised, the colder air from the surroundings enters into it, get heats up and the cycle repeats.
- The rising of the hot air transfers its heat into outer space and sinks back down.
- In this way, heat is transferred from hotter regions to colder regions. This is known as temperature regulation and the process of transferring heat is called convection.
- Moon has no atmosphere. Hence the temperature varies from 190°C to 110°C.
Other natural resources like water, land, plants, rivers, mountains, etc. play a vital role in sustaining life on earth by complementing each other. But one must not take these resources for granted. Due to population outburst, these resources are under great stress and measures need to be taken so that the future generation can also enjoy the luxury of nature like us.
WIND: THE MOVEMENT OF AIR
Air movement in coastal areas: In coastal areas, at daytime, there is a regular flow of cool air from the sea towards the land, whereas at night, there is a reverse flow of air from land to sea.
- DURING DAY: This happens because during the daytime, land gets heated faster than water. The hot air rises from the land and creates an area of low pressure. Whereas sea water does not get heated so rapidly. That means air above the sea is relatively cool and creates a high pressure as compared the air over land. Therefore, cooler air over the sea, flows toward the area where low pressure exists. The movement of air from one region to the other creates winds.
- DURING NIGHT: Reverse flow of air occurs at night. Land cools down rapidly making the air above the land cooler. This gives high pressure over the land. Sea water cools down slowly. The air above the sea is hotter and has a lower air pressure as compared to air pressure above the land. Therefore, cooler air present over land flows towards sea.
Factors Influencing Movements of Air
The following factors influence the movement of air:
- Uneven heating of land at different parts of Earth.
- Rotation of Earth.
- Presence of high mountain ranges in the path of winds.
- Vaporization and condensation of water vapors.
- Difference in topography over which the wind passes.
- Differences in heating and cooling of land and water bodies.