ATMOSPHERE STRUCTURE

ATMOSPHERE

The envelope of gases surrounding the earth or another planet

THE STRUCTURE OF THE ATMOSPHERE

             The atmosphere is broadly divided into four major zones viz. Troposphere, Stratosphere, Mesosphere and Thermosphere.

TROPOSPHERE

         Troposphere is the layer of air nearest to the ground. Temperature decreases with height. The average temperature drops from 15ºC at sea level to –56.5ºC at 11,000 m above sea level.

STRATOSPHERE

         Stratosphere is the layer of air above the troposphere where temperature increases with height. The average temperature rises to –2.5ºC at 50,000 m above sea level. Ozone is found in higher concentrations between 20 and 30 km above the surface

MESOSPHERE

          Mesosphere is the layer of air above the stratosphere where temperature decreases with height. The average temperature decreases to –90°C at 90,000 m. This is the coldest layer of the atmosphere.

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THERMOSPHERE

             Thermosphere is the layer of air above the mesosphere. The temperatures in the thermosphere increase with increasing height, but there are not many molecules in this layer. The air becomes less and less dense as we reach space.

BIOTIC COMPONENTS

              The live component of an ecosystem comprises plants, animals, and microorganisms (Bacteria and Fungi). They carry out different functions and based on their role they are classified into three main groups. They are:

(1) Producers

(2) Consumers

(3) Decomposers

              Producers are mainly green plants having chlorophyll. They produce carbohydrates by photosynthesis process.

             Consumers are living things, which do not have chlorophyll, and hence they are unable to produce their own food. They rely on the producers for their food requirements

             Decomposers are mainly microorganisms like Bacteria and Fungi. The dead organic materials of producers and consumers are their food.