Science for Environmental Technicians
Atmosphere
- It is a protective layer around the earth.
- It is composed of 5 layers.
- The temperature and pressure varies in each layer.
Note: The atmosphere is a protective blanket that protects the earth from cosmic rays. The atmosphere provides the necessary gases to sustain life. It takes part of many cycles that make the earth a habitable place. These cycles include the hydrological cycle (water), carbon, nitrogen, sulphur etc.
- It is a protective layer around the earth.
- It is composed of 5 layers.
- The temperature and pressure varies in each layer.
Note: The atmosphere is a protective blanket that protects the earth from cosmic rays. The atmosphere provides the necessary gases to sustain life. It takes part of many cycles that make the earth a habitable place. These cycles include the hydrological cycle (water), carbon, nitrogen, sulphur etc.
Note: The atmosphere is layered on the basis of temperature/density relationship. These relationships result from interactions (physical or chemical) process in air. The closest to the Earth’s surface is called the troposphere. The troposphere is generally characterised by homogeneous (equally proportional) gaseous composition. The temperature in the troposphere will decrease with altitude, since the Earth’s surface will be heated up by the UV rays and IR rays it absorbs. The upper limit of the troposphere can reach -56*C.
The homogenious gaseous mixture is achieved by air circulation (wind), exept water vapour.
The stratosphere is the next level. The temperature in the stratosphere will increase. It may increase up to -2*C. This temperature increase is due to the ozone layer (this layer will absorb the incoming UV rays and hence increasing the temperature).
The mesosphere is the layer that doesn’t contain much particles. This lack of particles will cause the temperature to decrease. At the altitude of 85km the temperature drops to 92*C.
The thermosphere is a highly rarified gas (not containing much particles/ thin) that reaches the temperature of 1200*C. This temperature is reached because the particles are constantly being ionised by the high energy waves.
The stratosphere is the next level. The temperature in the stratosphere will increase. It may increase up to -2*C. This temperature increase is due to the ozone layer (this layer will absorb the incoming UV rays and hence increasing the temperature).
The mesosphere is the layer that doesn’t contain much particles. This lack of particles will cause the temperature to decrease. At the altitude of 85km the temperature drops to 92*C.
The thermosphere is a highly rarified gas (not containing much particles/ thin) that reaches the temperature of 1200*C. This temperature is reached because the particles are constantly being ionised by the high energy waves.