ATMOSPHERE AND WEATHER, p476-483 SURFACE PROCESSES: ATMOSPHERE AND WEATHER, p476-483

Felix Baumgartner’s “Space” Jump https://www.youtube.com/watch?v=E9oKEJ1pXP w

What’s the difference between Weather and Climate? Weather – local, constantly changing, state of the atmosphere at any given time and place. Climate –based on observations of weather that have been collected over many years. Climate helps describe a place or region.

What’s the difference between Air and Atmosphere? Air is a mixture of different gases, water vapor, and particles (dust, pollution). Atmosphere is any gaseous mixture surrounding a planet or moon. 

Atmosphere and Air On Earth, we often refer to our atmosphere as “air”. When we breathe in air, we breathe in atmosphere. The air we breathe contains Gases (78% nitrogen, 21% oxygen, other) Water (water vapor, droplets, ice crystals) Solid Particles (dust, salt from oceans, ash from volcanoes)

How did our atmosphere form?

How did our atmosphere form? p9 Original atmosphere is thought to come from a mixture of gases that erupted from volcanoes (mostly water vapor, carbons dioxide and sulfur gases – very little oxygen) As plants began to grow, they produced oxygen through photosynthesis. 

What’s the difference between Air and Atmosphere? Which gas is most abundant in our atmosphere? How much Oxygen is in out atmosphere?

Where do the gases come from? Oxygen – from plants Nitrogen – decay of dead plants and animals Carbon dioxide – exhalation from animals, burning fossil fuels, volcanic eruptions Water vapor – evaporating water, plants, volcanic eruptions

WHY IS ATMOSPHERE IMPORTANT?

1. Gases in our atmosphere Sustain life: Oxygen - needed for cellular respiration. Carbon dioxide - for photosynthesis. Nitrogen - for building proteins and plant growth, Water vapor leads to weather near earth’s surface: source of all clouds and precipitation, absorbs heat given off by Earth, absorbs some solar energy.

Phosphorous in the air http://www.rsc.org/learn-chemistry/resource/res00001245/its-a- gas-part-1#!cmpid=CMP00002445 Discovery of oxygen video demo http://www.rsc.org/learn-chemistry/resource/res00001245/its-a- gas-part-1#!cmpid=CMP00002446 Oxygen and plants: http://www.rsc.org/learn- chemistry/resource/res00001245/its-a-gas-part- 1#!cmpid=CMP00002447

2. Our atmosphere helps regulate temperature (pg. 486): Greenhouse gases (carbon dioxide, methane, water vapor and ozone ) trap heat in the atmosphere keeping Earth warm. Without the atmosphere or greenhouse gases, the earth’s temperatures would be scorching during the day and frigid at night.

IMPORTANCE OF ATMOSPHERE Heat comes from Infrared radiation from the sun striking Earth, warming the surface and reflected back

How do Humans Influence on Atmosphere Emissions from transportation vehicles account for nearly half the air pollutants that create green house gasses. Increased greenhouse gasses causes Global Warming

WHAT IS OZONE? Ozone is O3 (three oxygen atoms bonded together) Ozone forms naturally when UV rays from the sun break up an O2 molecule, forming two single oxygen atoms, which then combine with other O2 already in the atmosphere.

WHY IS OZONE IMPORTANT? Ozone absorbs 99% of the dangerous short wavelength Ultraviolet radiation (UVR) from the sun. UVR can cause sunburns, skin cancer, and plant damage.

WHERE IS OZONE FOUND? Most ozone is found in the earth’s stratosphere, (Upper atmosphere)  10 - 50 km above us.

CFC’s Ozone is destroyed by chlorofluorocarbons (CFC’s). CFC were used primarily in aerosol sprays, refrigerants, and foam products.

CFC’s CFCs do not break up easily and eventually are released in the atmosphere where the chlorine can break down ozone in presence of sunlight. A single CFC molecule can destroy 100,000 ozone molecules.

OZONE HOLE There is a hole in the ozone layer over Antarctica first noted in 1979. This region’s low temperatures speed up the conversion of CFCs to chlorine.

What is Air Pressure? Air pressure is force of air molecules pushing on a surface. We don’t notice air pressure because our bodies are used to it.

Air Pressure decreases with altitude The higher you go, the lower the air pressure because there are fewer atoms pressing down the higher you go.  We don’t notice air pressure because our bodies are used to it.

Air Temperature changes with Height There are different layers of atmosphere, each made of a different combination of gases. Some gases absorb energy from the sun better than others. When a gas absorbs energy form the sun, air temperature goes up.

Air Temperature changes with Height The higher you go, the less gas molecules there are because there is less pressure keeping the particles together. The less particles crashing into each other, the less heat retained (kept).

Layers of Atmosphere There are four main layers of atmosphere based on temperature.

TROPOSPHERE – Lowest Layer Almost 90% of the gases in the atmosphere, most of the water vapor (~99%), carbon dioxide, pollution, and living things exist here. Densest layer (due to full weight of atmosphere pushing down) Warmest part is nearest to Earth’s surface (heat from Earth) Weather (wind and rain) occurs here. Surface to 18 km at equator, 8 km at poles Greek word 'Tropos' means 'change’. The layer we live in.

TROPOSPHERE – Lowest Layer As you move higher into the troposphere, both air temperature and air pressure decrease ‘Tropos’ – Greek word for ‘change’ Transitional area between the troposphere and stratosphere is called the tropopause – aircraft may fly in tropopause to avoid turbulence Greek word 'Tropos' means 'change’. The layer we live in.

STRATOSPHERE: 7-17 km to 50 km Gases are layered. Temperature starts to increase at about 15km, due to ozone absorbing energy from the sun. Air is stable because warm (less dense) air sits above cool (more dense) air Jet aircraft fly here because there is little air turbulence clear and dry, strong, steady winds "space jump"

MESOSPHERE 50-85km Temperature begins to drop again. Top part of mesosphere is the coldest part of atmosphere (because there are not very many gas molecules to absorb the sun’s radiation). Can be as low as -93C. Most meteors vaporize (burn up) in the mesosphere

Why do meteors burn up in Mesosphere? The meteors make it through the exosphere and thermosphere without much trouble because those layers don't have much air.  But when they hit the mesosphere, there are enough gases to cause friction and create heat.

Thermosphere (Ionosphere and Exosphere) 640 km above Earth The atmosphere is very thin Much of sun’s X-ray and UV radiation is absorbed here. Temperature rises again due to nitrogen and oxygen atoms absorbing solar energy The space shuttles orbit in the thermosphere. Temp rises again due to nitrogen and oxygen atoms absorbing solar energy. Up to 1000C. Uppermost layer ‘therm’ means heat

Temperature increases again The thermosphere absorbs much of the energy from the sun. It absorbs x rays and ultraviolet radiation from the sun and converts it into heat. The Thermosphere doesn't feel warm even though it is at up to 2500 C because it is so close to being a vacuum.

IONOSPHERE (upper mesosphere and lower thermosphere) Between 65-500km is a layer of highly ionized air (free ions and electrons, mostly nitrogen and oxygen ions) An ion is an atom that has lost or gained an electron. Ion formation (ionization) occurs when UVR knock electrons off oxygen atoms  Ionosphere forms 4 layers:

IONOSPHERE Ionosphere reflects radio waves of different wavelengths. Radio waves from broadcasting stations travel in straight lines. Radio waves bounce off the ionosphere allowing communication with countries overseas.

IONOSPHERE Ionosphere is affected by solar events: Huge eruptions on the sun send out large amounts of very short-wave radiation, which disrupts radio communications.  Sunspots, storms on the sun's surface, may cause intense magnetic activity like solar flares that can disrupt radio communications Peak every 11 year.

IONOSPHERE Auroras occur here: shimmering colored lights form when charged particles from the sun collide with the ions in the ionosphere. Ted Ed https://www.youtube.com/watch?v=czMh3BnHFHQ

How do auroras form? Ted Ed https://www.youtube.com/watchv=czMh3BnHFHQ

EXOSPHERE - highest layer extends up to 10,000 km above the Earth. Satellites orbit the Earth in the exosphere. The atmosphere in this layer is extremely thin and atoms and molecules of air are constantly escaping into outer space. Free-moving particles move in and out of the solar wind in the exosphere.

ATMOSPHERE HAS CHANGED https://www.youtube.com/watch?v=sturoUChNo4

Practice Read pages 480-482 Complete Atmosphere WS

Alternate Practice Read p477-482 Answer p483 #1-6 Interactive: http://www.glencoe.com/sites/common_assets/sci ence/virtual_labs/ES14/ES14.html

Alternate Practice Label the atmosphere WS Create a story or a comic strip of you moving through the layers of the atmosphere, describing what you feel and see.