Earth's Atmosphere

The atmosphere is a mixture of nitrogen (78%), oxygen (21%), and other gases (1%) that surrounds Earth. High above the planet, the atmosphere becomes thinner until it gradually reaches space. It is divided into five layers. Most of the weather and clouds are found in the first layer.

The atmosphere is an important part of what makes Earth livable. It blocks some of the Sun's dangerous rays from reaching Earth. It traps heat, making Earth a comfortable temperature. And the oxygen within our atmosphere is essential for life.

Over the past century, greenhouse gases and other air pollutants released into the atmosphere have been causing big changes like global warming, ozone holes, and acid rain.

<a href="/earth/Atmosphere/clouds/mammatus.html&edu=high&dev=1/earth/Atmosphere/moons/���">Mammatus clouds</a> are pouches of clouds that hang underneath the base of a cloud. They are usually seen with <a href="/earth/Atmosphere/clouds/cumulonimbus.html&edu=high&dev=1/earth/Atmosphere/moons/���">cumulonimbus clouds</a> that produce very <a href="/earth/Atmosphere/tstorm.html&edu=high&dev=1/earth/Atmosphere/moons/���">strong storms</a>. This photograph of mammatus clouds was taken on June 21, 2006 in Boulder, Colorado, at sunset. Notice how the light from the sun highlights the round features of these clouds.<p><small><em> Courtesy of Roberta Johnson</em></small></p><a href="/earth/Atmosphere/NLC.html&edu=high&dev=1/earth/Atmosphere/moons/���">Noctilucent</a> clouds are the highest clouds in the sky, but they are not associated with weather like the <a href="/earth/Atmosphere/clouds/cloud_types.html&edu=high&dev=1/earth/Atmosphere/moons/���">other clouds</a> we regularly see in the sky. Noctilucent clouds form very high in the <a href="/earth/Atmosphere/overview.html&edu=high&dev=1/earth/Atmosphere/moons/���">atmosphere</a>, in the <a href="/earth/Atmosphere/mesosphere.html&edu=high&dev=1/earth/Atmosphere/moons/���">mesosphere</a>. They are best seen from Earth at sunset. This image was taken on June 15, 2007, in Budapest, Hungary. Normally seen from locations near the <a href="/earth/polar/polar.html&edu=high&dev=1/earth/Atmosphere/moons/���">poles</a> of the Earth, in recent years they have also been seen at much lower-latitude locations.<p><small><em> Image Courtesy of NASA/Veres Viktor</em></small></p><a href="/earth/Atmosphere/clouds/stratocumulus.html&edu=high&dev=1/earth/Atmosphere/moons/���">Stratocumulus clouds</a> belong to the <a href="/earth/Atmosphere/clouds/low_cloud.html&edu=high&dev=1/earth/Atmosphere/moons/���">Low Cloud</a> (surface-2000m) group. These clouds are low, lumpy, and gray. Only light <a href="/earth/Atmosphere/precipitation.html&edu=high&dev=1/earth/Atmosphere/moons/���">precipitation</a>, generally in the form of <a href="/earth/Atmosphere/precipitation/drizzle.html&edu=high&dev=1/earth/Atmosphere/moons/���">drizzle</a>, occurs with stratocumulus clouds. To distinguish between a stratocumulus and an <a href="/earth/Atmosphere/clouds/altocumulus.html&edu=high&dev=1/earth/Atmosphere/moons/���">altocumulus</a> cloud, point your hand toward the cloud. If the cloud is about the size of your fist, then it is stratocumulus.<p><small><em> Courtesy of Carlye Calvin/UCAR</em></small></p><a href="/earth/Atmosphere/clouds/lenticular.html&edu=high&dev=1/earth/Atmosphere/moons/���">Lenticular clouds</a> form on the downwind side of mountains. <a href="/earth/Atmosphere/wind.html&edu=high&dev=1/earth/Atmosphere/moons/���">Wind</a> blows most types of clouds across the sky, but lenticular clouds seem to stay in one place. Air moves up and over a mountain, and at the point where the air goes past the mountaintop the lenticular cloud forms, and then the air <a href="/earth/Water/evaporation.html&edu=high&dev=1/earth/Atmosphere/moons/���">evaporates</a> on the side farther away from the mountains. This close up of lenticular clouds was taken at sunset on November 20, 2006 in Boulder, Colorado.<p><small><em> Courtesy of Roberta Johnson</em></small></p>On May 20, 2013, a massive EF5 <a href="http://www.windows2universe.org/earth/Atmosphere/tornado.html">tornado</a> hit Moore, Oklahoma, devastating communities and lives. The tornado, on the ground for 40 minutes, took a path through a subdivision of homes, destroying block after block of homes, and hitting two elementary schools just as school was ending as well as a hospital. Hundreds of people were injured, and 24 were killed.<p><small><em>Image courtesy of Ks0stm, Creative Commons Attribution-Share Alike 3.0 Unported license</em></small></p>Does Earth science matter? The power outage experienced by residents in New York City on 10/30/2012 due to Hurricane Sandy demonstrates the interconnectedness of our society, and the power of the Earth system. Every person should have an understanding of how the Earth system works so they can live better lives, protect those they love, and make wise choices. Earth science education is critical!<p><small><em>Image courtesy of Hybirdd, licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license.</em></small></p>

Explore Earth's Atmosphere

Layers of the Atmosphere

The atmosphere is divided into five layers. It is thickest near the surface and thins out with ...Read more

Weather

Weather is the state of the atmosphere at a given time and place. Most weather takes place ...Read more

Climate

Warm near the equator and cold at the poles, our planet is able to support a variety of living ...Read more

The Polar Atmosphere

Phenomena in the Polar Atmosphere There are some unique phenomena that happen in the atmosphere ...Read more

Atmospheric Optics

Have you ever seen clouds in the sky that looked different than "normal" clouds? Or have you ...Read more

Air Pollution

What do smog, acid rain, carbon monoxide, fossil fuel exhausts, and tropospheric ozone have ...Read more

Ozone Holes

The Ozone Hole is a major "thinning" of the ozone layer in Earth's atmosphere. It ...Read more

Modeling the Atmosphere

Clouds are an important part of Earth's weather and climate. Scientists use computer models ...Read more

Arts and Culture About Clouds, Weather, and Climate

Whether it is how an artist paints the shapes of clouds or how a poet describes a gloomy weather ...Read more

Atmosphere News

Read about current science, happenings and discoveries related to Earth's atmosphere! ...Read more

More about Earth's Atmosphere

Historical Events

Full Earth and Space Science    History Calendar (Members only)

Teacher Opportunities

Full Teacher Events Calendar (Educator Members only)

Did you know?

Did you know that the upper atmosphere of the Earth overlaps with the Earth's ionosphere?

Did you know that you can now share your poems about our collection of cloud art photos. Have fun!

 

Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Asperity
xAsperity : An asperity is an area on a fault that is stuck.

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Research Highlights

Pollution from Asia Circles Globe at Stratospheric Heights

The economic growth across much of Asia comes with a side effect: pollutants from the region are wafting up to the stratosphere during monsoon season. The new finding, in a study led by scientists at the...Read more


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