Introduction to the Atmosphere

“When you look out across our atmosphere, it looks like the skin of an onion.” Explain what this statement means.

The Atmosphere - the blanket of gases that surrounds the earth - is needed for more than just breathing. Name two other ways life here on Earth depends on the atmosphere.

- blocks out much harmful sunlight such as ultraviolet rays. - creates the greenhouse effect allows some sunlight in, traps it, and keeps Earth’s temperature steady - water evaporates and collects in the atmosphere, which influences weather.

The Atmosphere - and most everything else - is held in place by the force of GRAVITY. The more mass a body has, the greater its gravitational pull. Therefore, EARTH has more pull on the atmosphere.

The Atmosphere thins steadily with increasing elevation above the Earth’s surface.

Count the number of air molecules found in each elevation. O O O O O 160 km above sea level O O O O 80 km above sea level O O O O O At at sea level Count the number of air molecules found in each elevation. Explain why there is a difference.

Thus, the atmosphere thins rapidly with (decreasing, increasing) Therefore, (more, less) gas molecules are found near the surface than higher up. Thus, the atmosphere thins rapidly with (decreasing, increasing) distance above the Earth. More (2)increasing

As we travel higher into the atmosphere, the particles of air become ________. We say that the density of the air _______. Scientists have divided the atmosphere into _____ layers. Farther apart Decreases c.Four

- Is the atmosphere exerting some force on you? - How do you know? What is this force called? What part of the atmosphere is this force the greatest? Why? Yes (2)measured by a barometer (3)atmospheric pressure (4)greatest near the surface, more molecules are found near the earth’s surface

What factors change in the atmosphere as one increases its elevation? The word “pause” means what? What factor do you think is “pausing” in the atmosphere? Look at the diagram on the left. How can you tell that it is “pausing? “

Layers of the Atmosphere Exosphere Ionosphere Thermosphere Mesosphere Stratosphere Troposphere

Temperature Changes in the Atmosphere What is measured in the X-axis? What is measured in the y-axis? What pattern do you see? Look for the letter “x”. There is a “pause” here. Explain why the temperature reading is “pausing?” X Temperature Elevation Trop (decre) Strat (Incre) Meso (decre) and Thermo (incre) X

Troposphere Facts From surface - 10km (6 mi) Prefix “tropo” in Greek means “change” All of earth’s weather occurs here Most of the atm carbon dioxide and water vapor Life exists in the troposphere To 10 km=6 miles

Troposphere Facts 2 warmed by heat reflected from the earth’s surface energy from the sun passes through it Temperature decreases as altitude increases temperature drops about 6.5o C for each kilometer above the earth 23 F/mile?

Stratosphere Facts From Tropopause to 50 km (31 mi) Lower level is very cold Ideal altitude to fly planes. Ozone layer is in this layer Thickest at 25km Due to the Ozone layer, temperature increases in the upper stratosphere Ozone layer most consentrated at 25km = 16 miles Radiation breaks o2 to combine w/ o2 to get o3 Stratosphere from 10-50 km

Mesosphere Facts temperature drops as altitude increases coldest region of the entire atmosphere From Stratopause to 80 km (50 mi.) protects earth from meteoroids

Thermosphere Facts no well defined upper limit Thermo means “heat” in Greek Temp increases with altitude While the overall temperature is low in this sphere, individual particles may reach 2,000 degrees C. Contains the: Ionosphere exosphere

Ionosphere Facts contains charged particles called “ions” From 80-550 km (50-340 mi) absorbs ultraviolet and X-ray radiation from the sun radio signals are reflected back to Earth; makes long-distance communications possible

Exosphere Facts Upper part of Thermosphere Artificial satellites travel here Very few air particles in this layer

Get a Piece of Binder Paper

Atmosphere Quiz The Earth’s atmosphere is mostly composed of ___, ____, and ____. 2. Your ear makes a “pop” sound as you descend in an elevator. This is due to the changing _____. 3. What are the different layers making up the atmosphere (lowest to the highest layer)? 4. This layer is able to protect the Earth from harmful amounts of ultraviolet radiation. 1, nitrogen, oxygen, water vapor. Pressure Troposphere, stratosphere, mesosphere, thermosphere Ozone layer.

Atmosphere Quiz What is the relationship between density and the altitude of the atmosphere? What is the relationship between pressure and the altitude of the atmosphere? As altitude increases, density decreases. As altitude increases, pressure decreases.