The Atmosphere BIG IDEAS Earths atmosphere is a

The Atmosphere BIG IDEAS: Earth’s atmosphere is a mixture of gases that moves heat and allows life to exist on Earth. Weather patterns are created from interactions among ocean currents, air masses & topography.

Purposes of our atmosphere: – breathing (oxygen)– (You can survive for a few days without food or water but less than 5 minutes without the oxygen) – protects us from harmful solar rays (like UV and gamma) – warmth (traps heat) – water/water vapor – protection from most meteoroids

What makes up air?

What makes up DRY air? – 78% nitrogen--used to make protein – 21% oxygen (from photosynthesis)— processes that use oxygen: • cellular respiration (plants and animals) • oxidation (like rust, tarnish) • combustion (burning) --1% other gases (argon, carbon dioxide, dioxide other)

Air also contains… – human pollution (smog, etc) – natural pollution: dust, volcanic ash, sea salt, dirt, pollen, smoke from forest fires – water vapor--amount varies 0 -4% (humidity) ~ invisible gas – liquid water (cloud droplets and rain) – solid water (ice and snow)

Layers of the Atmosphere 1 closest The troposphere is the layer to Earth's surface. It is 7 to 20 km thick, and contains half of Earth's atmosphere. Air is warmer near the ground and gets colder higher up. Earth’s weather occurs in the troposphere. Nearly all of the water vapor and dust in the atmosphere are in this layer and that is why clouds are found here. Average temperatures range from 17°C(62°F)

Layers of the Atmosphere 2 The stratosphere is the second layer. It starts above the troposphere and ends about 50 km above ground. Ozone is abundant here, it heats the atmosphere while also absorbing harmful radiation from the sun. There is a hole in the ozone layer over Antarctica. Air in the stratosphere is very dry, and it is about 1000 times thinner here than it is at sea level. Because of that, this

Layers of the Atmosphere 3 The mesosphere starts at 50 km and extends to 85 km high. The top of the mesosphere, called the mesopause, is the coldest part of Earth's atmosphere, with temperatures averaging about -90 C(-130°F) meteors burn up in this layer.

Layers of the Atmosphere 4 about The thermosphere extends from 90 km to between 500 and 1, 000 km. Temperatures increase as you go up and can get up to 1, 500°C(2, 700°F) at this altitude. The thermosphere is considered part of Earth's atmosphere, but air density is so low that most of this layer is what is normally thought of as outer space. This is where the ionosphere is found, space shuttles fly, and the International Space Station

The Ionosphere The ionosphere is located within thermosphere. The ionosphere gets its name because nitrogen and oxygen molecules are ionized by solar radiation. In the process of ionization, the neutrally-charged molecules absorb high-energy, short-wavelength energy from the Sun. This causes the molecules to lose one or more electrons and become positivelycharged ions. The freed electrons

Layers of the Atmosphere The exosphere, the highest 5 layer, is extremely thin & is where the atmosphere merges into outer space. It is composed of very widely dispersed particles of H & He.