File:Earth-upper-atmosphere-NASA.jpg: Difference between revisions

The Earth's atmosphere does not abruptly end at any given height but becomes progressively thinner with altitude. The edge of most all of the atmosphere (80% approximately in the Troposphere) is not far above us.

The troposphere is one of five layers of the atmosphere surrounding the earth. The other four layers include the stratosphere, mesosphere, thermosphere, and exosphere. The troposphere is the lowest layer of the atmosphere, closest to the earth's surface. Its depth is different at different regions of the earth, being deeper in the warmer regions and shallower in the colder regions. The word 'troposphere' is derived from the Greek word 'Tropos' which means 'change'.

The troposphere is located closest to the earth, followed by the stratosphere, mesosphere, thermosphere, and the exosphere. The troposphere contains approximately 80% of the mass of the atmosphere of the Earth and 99% of the total mass of Earth's atmospheric water vapor.

The transitional area between the troposphere and stratosphere is called the tropopause. The jet stream or 'river of air' as it is also referred to, is located just below the tropopause and moves at approximately 250 miles per hour. The troposphere extends from the earth's surface to approximately 33,000 feet (6.2 miles) high. However in warm regions like the equator it can rise as high as 65,000 feet (12 miles). In colder regions like the north and south poles, it may rise only as high as 23,000 feet (4 miles). The troposphere is not heated directly from the sun. Instead, the sun heats the ground and the ocean and this heat is then radiated into the troposphere.

Despite the fact that only a small percentage of the troposphere's gas is carbon dioxide, this is the determining factor in the earth's temperature...

20 kilometers = 12.42742 miles

25 kilometers = 15.53428 miles

30 kilometers = 18.64114 miles

Troposphere

The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.

Stratosphere

The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high. The ozone layer, which absorbs and scatters the solar ultraviolet radiation, is in this layer.

Mesosphere

The mesosphere starts just above the stratosphere and extends to 85 kilometers (53 miles) high. Meteors burn up in this layer

Thermosphere

The thermosphere starts just above the mesosphere and extends to 600 kilometers (372 miles) high. Aurora and satellites occur in this layer.

Ionosphere

The ionosphere is an abundant layer of electrons and ionized atoms and molecules that stretches from about 48 kilometers (30 miles) above the surface to the edge of space at about 965 km (600 mi), overlapping into the mesosphere and thermosphere. This dynamic region grows and shrinks based on solar conditions and divides further into the sub-regions: D, E and F; based on what wavelength of solar radiation is absorbed. The ionosphere is a critical link in the chain of Sun-Earth interactions. This region is what makes radio communications possible.

Exosphere

This is the upper limit of our atmosphere. It extends from the top of the thermosphere up to 10,000 km (6,200 mi).

Credit: NASA/Goddard

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