The Components Of Earth’s Atmosphere And How Our Climate Is Affected By Volcanic Eruptions
The atmosphere is all that lies between us, and the vast and unforgiving conditions of space. It absorbs energy from the sun, protects us from radiation, supports the cycle of water and other chemicals, and interacts with Earth’s magnetic fields to give us a climate capable of supporting life.
Without it there would be no water, no air, no life. So we must protect it. But to protect it, we must first understand it.
Climate change due to atmospheric damage is in the limelight of modern science. The burning of fossil fuels, methane emissions from livestock and even natural events such as volcanic eruptions can all contribute to greenhouse gas emissions. These emissions interrupt the atmospheric system and are believed to be the cause of changing climate conditions. Even though our Earth has many buffers that help to maintain its environment, the interactions between these systems are not yet fully understood and modern science aims to solve these puzzles.
This essay will review the components of Earth’s atmosphere and our modern climate, and how our climate can be affected by natural events such as large volcanic eruptions.
When we look up to the sky mostly we see clear sky, straight to the sun, straight to the moon, straight to the stars. But there is a whole lot going on in that seemingly clear space. Figure 1.1 shows gives a “behind the scenes” glimpse of the many systems that are hard at work supporting the balance of our climate and protecting our planet.
Figure 1.1 (Wikimedia, 2012)
The atmosphere is best described as a series of concentric circles enveloping our earth. Each circle is layer with a unique chemical composition, temperature range and function.
Chemical Composition of the Atmosphere
The current molecular composition of Earth’s atmosphere is diatomic nitrogen (N2), 78.08 percent; diatomic oxygen (O2), 20.95 percent; argon (A), 0.93 percent; water (H20), about 0 to 4 percent; and carbon dioxide (CO2), 0.038 percent. Inert gases such as neon (Ne), helium (He), and krypton (Kr) and other constituents such as nitrogen oxides, compounds of sulfur, and ozone are found in lesser amounts (Britannica, 2012).
Table 1.1 lists the chemical components in descending order of their respective percentage volume within our atmosphere.
Table 1.1 (GeoStatic, 2012)
Based on the chemical composition, the atmosphere can be divided into two major zones, the homosphere and heterosphere.
The Homosphere – The homosphere is the lower of the two and the location in which turbulent mixing dominates the molecular diffusion of gases (Britannica, 2012). In this region, which occurs below 90 km or so, the composition of the atmosphere tends to be independent of height. The density of the atmosphere rapidly increases towards Earth’s surface but the blend of gases stays the uniform. The only exception to this is the concentrated layer of ozone, which lies between 18 and 50 km above the surface of the earth. This layer is vital for absorbing the bulk of the sun’s ultra violet rays (Christopherson, 2012).
The Heterosphere - Above 90 km is the heterosphere. In this zone, gases are not uniformly mixed. The atmospheric gases are separated by their atomic weights, with the lighter gases helium and hydrogen) being concentrated in the highest layers and the heavier gases (oxygen and nitrogen) being closer to Earth (Christopherson, 2012).
Temperature Gradient of the Atmosphere
The atmosphere can be segmented into several distinct layers defined by changes in air temperature with increasing height above the Earth’s surface. The position of these layers can be seen in Figure 1.2.
Troposphere - The lowest part of the atmosphere is the Troposphere. This layer contains most of Earth’s clouds and is the...
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