Monday, January 26, 2015
by Antonio C. Antonio
January 24, 2015
So far, the Earth in the only known planet that has an atmosphere that is capable of supporting life. It now becomes a saddening fact that we have largely taken our atmosphere for granted. More often, the only time we become concerned about the atmosphere is when the weather and pollution indices are bad. The only time we show concern for the atmosphere and the environment in general is when global warming rises to the level that makes life unbearable, climate and weather patterns change for the worse to the point where countless lives are lost, and basic life support system Mother Earth provides has degenerated to a point where diseases are very common occurrences. It should be noted that these disastrous effects are caused by anthropogenic activities.
The atmosphere is composed of four distinct layers or atmospheric zones of contrasting temperature. The difference in temperature is caused primarily by the variation in solar energy absorption. A clear understanding of the characteristics of these atmospheric zones will help us understand atmospheric functions. The following are these thin layers of air in the atmosphere:
TROPOSPHERE – The troposphere is the lowest layer of the Earth’s (or nearest to the Earth’s surface) atmosphere and site of all weather conditions on Earth. The troposphere is bonded on the top by a layer of air called tropopause which separates the troposphere from the stratosphere and on the bottom by the surface of the Earth.
STRATOSPHERE – The stratosphere is the second major layer of air in the Earth’s atmosphere which is above the troposphere and below the mesosphere. It is stratified in temperature with cooler air below that gradually warmer layers of air farther up or away from the surface of the Earth. Air temperature in this layer is stable although it increases with higher altitude. Ozone is produced by lighting and solar irradiation of oxygen molecules. It should be mentioned that ozone protects life on Earth by absorbing most solar and ultraviolet radiation from the sun that passes through the upper layers of the atmosphere.
MESOSPHERE – The mesosphere is the layer of the Earth’s atmosphere that is directly above the stratosphere and directly below the thermosphere. The mesosphere is located about 50 to 85 kilometers above the Earth’s surface.
THERMOSPHERE – The thermosphere is the layer of the Earth’s atmosphere directly above the mesosphere and below the exosphere. In this layer of air in the atmosphere, ultraviolet radiation (UV) causes ionization.
EXOSPHERE – The exosphere is the uppermost region of Earth’s atmosphere as it gradually fades into the vacuum of space. Air in the exosphere is extremely thin and in many ways it is almost the same as the airless void of outer space.
The layers of air in the atmosphere protects the Earth’s surface from abnormal exposure to solar radiation and foreign bodies coming from outer space. Smaller meteors and meteorites burn up as they hit the exosphere and are reduced to smaller masses before they hit the Earth’s surface. Protecting and supporting life forms on the surface of the Earth is the main function of the atmosphere.
Just my little thoughts…
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