210 likes | 222 Views
THE ATMOSPHERE. Learning Goal: Describe how the composition and structure of the atmosphere protects life on Earth. Essential Question: How does the composition and structure of the atmosphere protects life on Earth. Main Ideas:. The atmosphere is divided into laters .
E N D
THE ATMOSPHERE Learning Goal: Describe how the composition and structure of the atmosphere protects life on Earth. Essential Question: How does the composition and structure of the atmosphere protects life on Earth.
Main Ideas: • The atmosphere is divided into laters. • The atmosphere protects life from harmful radiation and regulates the planet’s temperature. • Weather is caused by changes in the atmosphere due to the transfer of energy in one form or another. • This energy transfer is driven by the solar radiation from the sun.
The Atmosphere • Atmosphere: the blanket of gasses that surrounds our planet held by gravity
The Early Atmosphere • Thought to be mostly water vapor and carbon dioxide. • Water vapor condensed and rained to fill the oceans. • The first organisms used carbon dioxide to perform photosynthesis which made oxygen.
Today’s Atmospheric Composition • 78% Nitrogen (N) • 21% Oxygen (O2) • 1% Other Gasses
The atmosphere also contains: • water vapor: which forms clouds and precipitation and absorbs heat energy • particles: like dust, salt, pollen • ozone: a gas in the ozone layer that absorbs harmful UV radiation. • Greenhouse gasses: gas molecules that absorb solar radiation, trap heat, and can increase the temperature of the atmosphere. • Carbon dioxide: most worrisome • Water vapor: most abundant
Atmospheric Layers • There are 5 layers of the atmosphere, divided by temperature. • Temperature is a measure of the average amount of kinetic energy of the particles in a material. (motion)
Layers from top to bottom: • Exosphere • Thermosphere • Mesosphere • Stratosphere • Troposphere
Exosphere (“Exo”- means outer) • outermost layer with no clear boundary • It extends into space
Thermosphere (“therm-” means heat) • Very little air here • Known for its great range of temperatures (-112⁰ F - 2000 ⁰ F) • Layer where space shuttles orbit • Produces the Aurora Borealis (Northern Lights)
Mesosphere (“Meso-” means middle) • Air is very thin • Temperature decreases. • Where meteors burn up and make shooting stars.
Stratosphere • Air is pretty thin • contains the “Ozone Layer” which is made of ozone gas that protects us from harmful UV radiation by absorbing it • This is why temperature in the stratosphere increases.
Troposphere • Bottom layer that contains most of the air. • Temperature decreases with altitude because the Earth’s surface warms it. • Where all weather occurs
Where all weather occurs. • The Sun heats the Earth through radiation. • The clouds block the sun during the day and keep heat in at night. • Water vapor and carbon dioxide also absorb heat and help keep it warm at night.
The ground absorbs the Sun’s radiation. • The ground heats the air above it through conduction. It gets cooler the farther away you get from the ground.
Convection TRIES to evenly distribute heat in the troposphere. • Warm, moist air rises, and cool air sinks and rushes in to replace it. This creates wind. • It is also how clouds form.
All three types of energy transfer happen in the troposphere.
Altitude is the height above sea level. • The higher you go, the less air there is.
Pressure is the weight of the air above you • The higher you go, the less air there is, so pressure decreases with altitude.