How is the tropopause different from the stratopause?

1. Atmosphere and its Composition:

(i) The atmosphere is the enormous blanket of air that surrounds the world.

(ii) Air is a mixture of gases and small dust particles. Two gases, Nitrogen and oxygen form a huge part of the total amount of gases in the air whereas carbon dioxide, helium, ozone, argon, hydrogen, and other gases form a lesser amount.

(iii) Nitrogen is important for the survival of plants.

(a) Plants depend on a type of bacteria that live in the soil and roots of some plants for their nitrogen intake.

(b) These bacteria can change the form of nitrogen which can be easily taken by plants.

(iv) Photosynthesis is the mechanism through which green plants create oxygen. Oxygen is also used for breathing by both humans and animals.

(v) Carbon dioxide is released by humans and animals while green plants use it in the process of photosynthesis.     

(a) This balance of releasing and using carbon dioxide has been disturbed by the burning of fuels.

(b) It has affected the earth’s weather and climate.

2. Structure of the Atmosphere:

(i) There are five layers in the atmosphere -Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere

(ii) In the Troposphere, weather events such as rainfall, fog, and hailstorm occur.

(iii) Stratosphere has ideal conditions for flying aeroplanes. Also, the stratosphere has a layer of ozone gas which protects us from the harmful effect of the sun's rays.

(iv) In the Mesosphere, meteorites which enter the orbit of earth from space burn up.

(v) Thermosphere contains a layer known as the Ionosphere which bounces back radio waves transmitted from the earth and helps in radio transmission.

(vi) Exosphere is the uppermost layer of the atmosphere which contains very thin air. Helium, hydrogen, and other light gases float into space from here.

3. Weather and Climate:

(i) Temporary conditions of the atmosphere such as hourly, daily, or weekly are known as the Weather.

(ii) Climate is the average weather condition for a longer time.

4. Temperature:

(i) Temperature of the atmosphere is the degree of hotness and coldness of the air. The temperature of a place during the day is different from during the night, and also it varies from season to season.

(ii) Insolation i.e., solar energy received by the earth affects the distribution of temperature. 

(a) From the equator to the poles, the amount of insolation decreases. As a result, the temperature at the equator is higher than at the poles.

(iii) There are some man-made features such as concrete and asphalt which also increase the temperature of a place.

5. Air Pressure:

(i) The pressure exerted by the weight of air on the earth’s surface is called Air pressure. Changes in air pressure are experienced horizontally as well as vertically.

(ii) Vertically, air pressure is highest at sea level and decreases as we go up.

(iii) Horizontally, low air pressure is experienced in areas of high temperature, and high air pressure is experienced in areas of low temperature.

6. Wind:

(i) The moving air is referred to as wind. It blows from high-pressure to low-pressure zones at all times.

(ii) There are three types of winds in general: Throughout the year, Permanent winds blow in a specific direction. The direction of Seasonal winds changes with the seasons. Local winds only blow in a narrow region during a specific time of day or year.

7. Moisture:

(i) Water that evaporates from land and different water bodies remains in the atmosphere as water vapours and moist the air. Moisture available in the air at any time is called humidity.

(ii) With the increase in temperature, the capacity of air to hold the water vapour increases.

(iii) Clouds are masses of water droplets. These water droplets are formed when water vapour rises, cools, and condenses.

(iv) When water droplets become heavy and cannot remain floating in the air, they fall as precipitation.

(v) Rain is a form of precipitation in liquid form. There are three types of rainfall on the basis of mechanism- convectional rainfall, orographic rainfall, and cyclonic rainfall.

(vi) Snow, sleet, and hail are other forms of precipitation.