Download Weather and Climate—Chapter 1, Section 1 Notes

Air and the Atmosphere
Atmosphere—layer of gases that surrounds Earth.
Weather—condition of Earth’s atmosphere at a particular time and place.
Importance of the Atmosphere:
Earth’s atmosphere makes conditions on Earth suitable for living things:
 Contains oxygen and other gases that living things need
 Traps energy from the sun, keeping it warm enough for water to exist
as a liquid and keeping the temperature suitable for life
 Protects living things from dangerous radiation from the sun
 Prevents Earth’s surface from being hit by most meteoroids
Composition of the Atmosphere:
Earth’s atmosphere is made up of nitrogen, oxygen, carbon dioxide, water
vapor, and many other gases, as well as particles of liquids and solids.
 78% Nitrogen—used to repair body cells (protein has nitrogen);
bacteria in the soil change nitrogen in the atmosphere to a form that
plants can use, and it moves through the food chain.
 21% Oxygen—used to release energy from food; ozone is a different
type of oxygen made when lightning reacts with the air
 Carbon dioxide—used by plants to make food; given off by animals
as a waste product; also released when fossil fuels are burned, which
may be causing Earth’s temperatures to rise (Global Warming, or the
Greenhouse Effect)
 water vapor—water in the form of a gas; invisible
 particles—dust, smoke, salt, and other chemicals