Why is 80 of the gas in the atmosphere in the troposphere

The atmosphere protects life on earth by shielding it from incoming ultraviolet UV radiation, keeping the planet warm through insulation, and preventing extremes between day and night temperatures.

The sun heats layers of the atmosphere causing it to convect driving air movement and weather patterns around the world. Teach your students about the Earth's atmosphere with the resources in this collection. 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. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Image Moon Earth Troposhere Silver-blue noctilucent clouds are shown extending far above the orange-colored troposphere, the lowest and densest part of Earth's atmosphere.

Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. Media If a media asset is downloadable, a download button appears in the corner of the media viewer.

Text Text on this page is printable and can be used according to our Terms of Service. Interactives Any interactives on this page can only be played while you are visiting our website.

Related Resources. View Collection. Parts of the Atmosphere. View Article. However, human activities also influence the concentration of carbon dioxide. They are not chemically active in the troposphere, but they do play an important role in stratospheric chemistry. Knowing the global budget of less abundant, but more reactive gases, and understanding the behaviour and distribution of these gases is important but difficult, because of the numerous and complex chemical and physical processes involved.

The driving forces behind this chemistry is solar radiation , in particular in the near ultra-violet UV-A and UV-B and to a lower extent also in the visible range. Solar radiation can indeed "break up" dissociate chemical molecules. The troposphere is protected from the hardest ultraviolet radiation by the stratospheric ozone layer. In spite of this efficient filtering of harmful UV radiation, solar radiation still can break up, for example, ozone and nitrogen dioxide molecules in the troposphere.

These dissociation processes initiate a complex series of chemical reactions, leading for example to the production of radicals like the hydroxyl radical OH. This radical plays a determining role, since it is responsible for the oxidation of many gases emitted at the Earth's surface that would otherwise accumulate in the troposphere. Using temperature, the atmosphere can be divided into 4 distinct zones. Temperature rises to 0 F 0 C and higher.

The Mesopause outer layer of Mesosphere is the coldest region in the atmosphere about — 0 F 0 C. Temperature increases with altitude. Home of the biosphere. Normal Lapse Rate : the phenomena by which temperature decreases rapidly with altitude.

Temperature Inversion: a phenomenon by which temperature increases with altitude. Based on function, the atmosphere has 2 zones that remove harmful solar radiation and charged particles:. I absorbs Cosmic rays, gamma rays, X-rays and Ultraviolet radiation. Absorbs UV light and re-radiates it as long wave infrared radiation.

The troposphere contains variable quantities of both natural and human-caused gases and chemicals that cause air pollution. Winds : move pollutants from one place to another reducing concentrating at one point while increasing it in another region. Mountains and Hills local landscape can form barriers to air movement or direct pollutants from one area to another. Temperature Inversion : Temperature inversion prevents the rise of cooler hence denser air to rise beneath thereby halting vertical mixing of pollutants and preventing winds from blowing.

Human-induced pollutants are found in Urban areas. Developed with the advent of the automobile. Industrial Smog and Sulfur Oxides:. Industrial smog is associated with coal-burning industries. Carbon monoxide. Incomplete combustion of fuels.