What does the atmosphere contain? How much nitrogen does the atmosphere contain?

How much oxygen does the atmosphere contain?

What does the atmosphere do?

How many layers does the atmosphere have?

List the layers of the atmosphere and two characteristics of each layer.

We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions.

Earth's atmosphere is composed of about 78% nitrogen, 21% oxygen, and one percent other gases. These gases are found in layers (troposphere, stratosphere, mesosphere, thermosphere, and exosphere) defined by unique features such as temperature and pressure.

Earth's atmosphere has five major and several secondary layers. From lowest to highest, the major layers are the troposphere, stratosphere, mesosphere, thermosphere and exosphere.

roposphere

The troposphere (between 0 and about 15 kilometers) is the first layer above the Earth’s surface and contains approximately 85 to 90 % of the mass of the Earth’s atmosphere. It is characterized by decreasing temperature with increasing altitude.

The troposphere’s thermal profile is largely the result of the heating of the Earth’s surface by incoming solar radiation. Heat is then transferred up through the troposphere by a combination of convective and turbulent transfer. Weather occurs in the Earth’s troposphere.

Stratosphere

In the stratosphere (between approximately 15 and 50 km) the temperature rises as a function of increasing height.

This warming is the result of the direct absorption of solar radiation by the ozone layer, thereby preventing a large part of harmful ultraviolet radiation from the sun to reach the Earth’s surface.

Mesosphere

The mesosphere is the next layer of the atmosphere (from 50 to 90 km), characterized by temperatures that decrease the further up one goes to an average of -90°C.

A lot of meteors burn up in this layer while entering the Earth’s atmosphere.

Thermosphere

Thereafter the thermosphere takes over where temperatures increases steadily with altitude. It is the layer of the atmosphere which is first exposed to the Sun’s radiation.

The thermosphere also includes the ionosphere, a region of the atmosphere that is filled with charged particles, where especially the auroras occur.

Exosphere

The upper limit of Earth’s atmosphere is the exosphere where the atmosphere merges into space.

Explanation:

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.