ATMOSPHERE is mixture of gases that surround the Earth. • About 99% of the atmosphere is composed of nitrogen and oxygen. • Nitrogen 78% and Oxygen 21% • The remaining one percent consisting of small amounts of argon, hydrogen, carbon dioxide, water vapor, and other gases.
AIR PRESSURE the measure of force with which air molecules push on a surface. • The gravitational attraction between Earth and atmospheric gases causes particles of gas to be pulled toward the center of Earth. • Atmospheric pressure decreases with height because there are fewer and fewer gas particles exerting pressure. • Change in Air pressure is what causes your ears to “Pop”, when your ear drum tries to equalize the pressure in your ear.
As you move from the surface upwards ↑ the air pressure decreases with fewer air molecules above you.Sea level pressure is 14.7 lbs per square inch
Layers of the Atmosphere • The atmosphere is made up of several different layers. TROPOSPHERE STRATOSPHERE MESOSPHERE TEROMOSPHERE EXOSPHERE • Each layer differs in composition and temperature.
TROPOSPHERE • The layer closest to Earth’s surface, the densest layer contains 90% of the atmosphere gases, including water vapor. • All life is found in it. • All weather takes place in the troposphere. • As you go up in the Troposphere the temperature and pressure DECREASES. • Sfc to 10,000 km/ 71/2 mi. thick
STRATOSPHERE • is where most ozone is located. • Planes fly in the lower Stratosphere because there is no weather to jostle the planes. • Temperature INCREASES with height due to the Ozone layer absorbing radiant heat from the Sun. Blocking most Ultraviolet energy. • 10,000 to 50,000 km/ 7to 30 mi thick
MESOPHERE • is the coldest layer of the atmosphere. • Temperature DECREASES with height. • This is where you would see meteors shooting through as they encounter more air molecules. • 50,000 to 80,000 km/ 30 to 50 mi. thick
THERMOSPHERE • The upper most layer of the atmosphere contains a very small part of the atmosphere’s mass mostly Nitrogen and Oxygen particles. • This is the hottest layer because it is closer to the sun and it absorbs the heat from it. • the IONOSPHERE which is made up of electrically charged particles is found in the Thermosphere where Auroras forms and radio waves bounce off it. • TEMPERATURE INCREASES with height. • 80,000 to 300,000 km/ 50 to 190 mi thick
Exosphere • The exosphere, which is composed of light gases such as helium and hydrogen, so satellites can travel here very easily • Molecules are actually traveling so fast that some are able to escape from earth’s gravity. • There is no clear boundary between the atmosphere and space.