The composition of atmospheric gases is about the same at different altitudes, with the important exception of the ozone layer. Despite being similar in its composition throughout, the atmosphere is divided into layers that are defined primarily by temperature gradient, which is the change of temperature that occurs with distance (or, in this case, altitude).
The layer nearest the Earth's surface, rising from sea level to about 6 miles (11 km), is the troposphere. The primary heat source for the troposphere is infrared energy (heat) that radiates from Earth's surface. This layer measures a decrease in temperature of about 3.6°F per
The layers of the atmosphere are defined by whether they increase or decrease in temperature with altitude, except the ozone layer, which is named for its relatively large concentration of ozone molecules.
1,000 feet (6.5°C per 1,000 m) of altitude. The value fluctuates with the day, the location, and the season. Sometimes a portion of the troposphere has a temperature inversion and the situation is reversed: Air temperature increases with height. Almost all of the weather found at the planet's surface is due to the vertical movement of air in the troposphere.
The stratosphere rises from the top of the troposphere to about 30 miles (45 km). Since this layer is heated by the Sun's UV rays, it gets warmer with increasing proximity to the Sun. The warm air of the upper stratosphere "floats" on the cooler air of the lower stratosphere, since it is less dense. With warmer air above cooler air, the stratosphere is very stable vertically. This layer usually experiences very little turbulence, which is why commercial airliners fly at this level. Not only does air within the stratosphere not mix, but also there is almost no mixing between the stratosphere and the troposphere beneath it. Ash and gases shot into the stratosphere by a volcanic eruption may remain there for many years.
The stratosphere contains the ozone layer, which lies between 9 and 19 miles (15 and 30 km) from the Earth's surface. Even here, the ozone concentration is quite small, measuring only about 12 ozone molecules for every 1 million air molecules. As small as it is, the ozone concentration is one reason that the stratosphere warms with altitude. The ozone molecules absorb the high-energy UV as they break apart into molecular oxygen (O2) and atomic oxygen (O).
Air density decreases in the layers of the atmosphere that lie beyond the stratosphere. In each of these layers, the air molecules are very far apart and the air is very cold. Beyond the atmosphere is the solar wind, which is made up of high-speed particles traveling rapidly outward from the Sun.
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Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.