Layers and Changes in Earth's Atmospheric Surface
The atmosphere is a layer of air that covers the earth as a whole with a thickness of more than 650 km. The movement of air in the atmosphere occurs mainly due to the influence of sunlight heating and earth's rotation. This earth's rotation will result in the movement of air mass, so that there will be differences in air pressure in various places in the atmosphere that can cause wind currents.
Atmospheric Evolution
According to geologists, in the beginning the earth's atmosphere contained (carbon dioxide) high levels, so the surface temperature of the earth was also high. At that time oxygen () had not yet been formed so there was no ozone layer in the stratosphere, because of that ultraviolet light from the sun reaching the earth's surface with a very strong radiation intensity. This condition is not possible for life, except there may be life in deep waters so as to avoid ultra violet rays.
About 3.5 billion years ago the evolution of chlorophyll living creatures began to enable the process of photositensis. Because photositensis requires the levels in the atmosphere to decrease and vice versa levels increase. Through this process the ozone layer () is formed.
Atmospheric Layers
Based on the vertical temperature profile, the layers of the atmosphere can be divided into
Troposphere (0 - 10 Km) Is the lowest atmosphere and close to the Earth. In this layer, there are clouds, wind, rain, lightning, and others.
Stratosphere (10 - 30 Km) In this layer, an increase in temperature due to increased altitude. Ozone (O3) is found in this layer with a height of 25 Km from the surface of the Earth.
Mesosphere (30-50 Km) This layer has electrically charged ions or air (Layer D) which functions to reflect radio waves. Because of the electric charge, we can communicate with other people abroad.
Thermosphere (50 - 400Km) This layer serves to protect the earth from meteors by burning it. This is because the atmospheric layer has electrically charged or ionized solar radiation
Exosphere> 400 Km Is the highest layer of the atmosphere. In this layer, the content of atmospheric gases is very low. The boundary between the ekosfr (which is basically also the boundary of the atmosphere) with outer space is not clear. Areas that are included in the ecosphere are areas that can still be affected by the earth's gravity. Imaginary lines that limit the ecosphere with outer space are called magnetopause.
Atmospheric Function
The existence of the atmosphere that covers the entire surface of the earth has a very important meaning for the survival of various organisms on earth. Atmospheric functions include:
Reducing solar radiation that reaches the earth's surface during the day and loss of excessive heat at night.
Distributing water to various regions of the earth's surface
Provides oxygen and carbon dioxide.
As a retaining meteor that will fall to earth.
The role of the atmosphere in reducing solar radiation is very important. If there is no atmospheric layer, the surface temperature of the earth if 100% of the sun's radiation is received by the surface of the earth will be very high and it is feared that no organism can understand life, including humans.
In distributing water between regions on the surface of the earth, the role of the atmosphere is seen in the hydrological cycle. Without an atmosphere capable of storing water vapor, then all the water on the surface of the earth will only collect at the lowest place.
The rivers will dry up, all the ground water will seep into the sea, so that the water will only collect in the ocean and sea. The distribution of water by the atmosphere provides opportunities for all living things to grow and develop throughout the earth's surface. In addition, the atmosphere can provide oxygen for living things. Plant's need for CO2 can also be obtained from the atmosphere.