In addition to their own resiliency, living things and the cells they are made of are protected from excessive amounts of UV radiation by a chemical called ozone. A layer of ozone in the upper atmosphere absorbs UV radiation and prevents most of it from reaching the Earth.

In the troposphere, ozone is an oxidant that can harm respiratory systems in animals and damage a number of structures in plants. However, in the stratosphere ozone forms a necessary, protective shield against radiation from the Sun; it absorbs ultraviolet light and prevents harmful radiation from reaching Earth.

Ozone

Ozone; O3 in the upper atmosphere protects living organisms by preventing damaging ultraviolet light from reaching the Earth’s surface. It is also low in concentrations through the Earth’s atmosphere. Ozone, O3, is a pale blue gas that is unstable and toxic.

Gases in Earth’s Atmosphere Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere’s mixture of gases.

Some references include other gases on this list, such as krypton (less abundant than helium, but more than hydrogen), xenon (less abundant than hydrogen), nitrogen dioxide (less abundant than ozone), and iodine (less abundant than ozone).

Earth’s atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapor, and neon are some of the other gases that make up the remaining 0.1 percent.

Key Concepts Earth’s atmosphere is made up of a combination of gases. The major components of nitrogen, oxygen, and argon remain constant over time and space, while trace components like CO2 and water vapor vary considerably over both space and time.

Composition of air

• Nitrogen — 78 percent.
• Oxygen — 21 percent.
• Argon — 0.93 percent.
• Carbon dioxide — 0.04 percent.
• Trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor.

thermosphere

mesosphere

E. The thermosphere contains a layer of charged particles called the ionospherewhich makes communication by radio wavespossible and is home to theaurora borealis(Northern Lights). This is the layer in which flew before it was grounded within the last decade..

A dense layer of molecules and electrically charged particles, called the ionosphere, hangs in the Earth’s upper atmosphere starting at about 35 miles (60 kilometers) above the planet’s surface and stretching out beyond 620 miles (1,000 km).

The atmosphere contains the air that we breathe; protects us from the harmful radiation of the Sun; helps to keep the planet’s heat on the surface, and plays a very important role in the water cycle. Without the atmosphere there would be no sound.

Biological Uses of Air Air is pulled into the body by lungs and used to fill tiny air sacs that allow blood cells to pick up oxygen, which is then distributed across the body’s cells. Through the process of cellular respiration, this oxygen can then be used to break down sugars and create energy.