Meteorology

1. Meteorology

2. Atmosphere • A thin blanket of gasses surrounding Earth • Gasses are held by Earth’s gravity • 99.9% of the atmosphere’s mass is located below 50km • Absorbs reradiated heat from Earth’s surface to provide a balanced temperature for life to survive.

3. Composition of The Atmosphere

4. Composition of the Atmosphere A. Air is a mixture of discrete gases B. Major components of clean, dry air 1. Nitrogen (N) – 78% 2. Oxygen (O2) – 21% 3. Argon and other gases 4. Carbon dioxide (CO2) – 0.036% – absorbs heat energy from Earth Mixture – material that contains two or more substances that are not chemically combined

5. C. Variable components of air 1. Water vapor a. Up to about 4% of the air's volume b. Forms clouds and precipitation c. Absorbs heat energy from Earth 2. Aerosols a. Tiny solid and liquid particles b. Water vapor can condense on solids c. Reflect sunlight d. Help color sunrise and sunset

6. 3. Ozone a. Three atom oxygen (O3) b. Distribution not uniform c. Concentrated between 10 to 50 kilometers above the surface d. Absorbs harmful UV radiation e. Human activity is depleting ozone by adding chlorofluorocarbons(CFCs)

7. The Composition of the Atmosphere • The percentage of nitrogen and oxygen are fairly constant throughout the atmosphere up to an altitude of about 80 kilometers. • Water vapor content varies with location, season, and time of day. Water vapor concentration is higher near the surface. (0 to 4% ) • Carbon dioxide in the air varies with the seasons. It is lowest during summer and highest during winter. Why?

8. The Composition of the Atmosphere • The atmosphere also contains a wide variety of dust particles. • Dust includes: tiny grains of rocks, dirt, pollen, salt crystals from sea spray, and soot from fires.

9. Structure of the atmosphere

10. A. Earth’s Gravity and Pressure changes 1. Pressure is the weight of the air above 2. Average sea level pressure a. Slightly more than 1000 millibars b. About 14.7 pounds per square inch

11. 3. Pressure decreases with altitude a. One-half of the atmosphere is below 3.5 miles (5.6 km) b. Ninety percent of the atmosphere is below 10 miles (16 km)

12. Functions of The Atmosphere • Protection of all life from hazardous or deadly radiation from space (filter for UV- and x-rays from sun). • Letting pass the vitally important sunlight to the surface of the continents and oceans (energy source). • Protections from rapid cooling at night and heating at day. • Makes possible a mean temperature on Earth's surface of +15 °C instead of -18 °C as would be without atmosphere. • Transport of energy (warmth of air that can be felt and latent warmth of water vapour) from the equatorial regions to medium and higher latitudes.

13. Function of the Atmosphere cont. • Transport of water vapor through dynamic processes of general air circulation that determines precipitation. • Storage of huge amounts of nitrogen (important for plants). • Reservoir for carbon dioxide and oxygen. • Is part of different vital cycles of matter. • Dissipation and decomposition (oxidation, reaction with radicals, photolysis) of natural and anthropogenic (man-made) emissions. • Protection from smaller meteorites that burn up by heating from the friction when entering the Earth's atmosphere and can not reach the surface.

14. Atmosphere Temperature Structure

15. Structure of the Atmosphere • The temperature of the atmosphere changes dramatically at varying altitudes. • Temperature differences are used to divide the atmosphere into four layers: troposphere, stratosphere, mesosphere, and thermosphere. http://www.youtube.com/watch?v=3CerJbZ-dm0&list=RDQeAp3CuGjk8

16. The Troposphere • “Tropo” means change or churning. • The lowest layer of our atmosphere. • Temperature decreases with altitude. • It is primarily Nitrogen (N) 78% and Oxygen (O) 21%

17. Troposphere • The rate of cooling with altitude is highly variable, but averages about 6.5°C for each kilometer in altitude gain. (lapse rate ) • The Troposphere contains about 80% of the total mass of the atmosphere and most of the water vapor in our atmosphere. • Thickness varies – average height is about 12km • Almost all weather occurs in the Troposphere. • 7-20 km (4-12 miles) – most clouds are here

18. Temperature Altitude Temperature and Altitude Troposphere Write a hypothesis expressing the relationship of altitude and atmosphere temperature. 0 Temperature and Altitude are indirectly related

19. The Tropopause • The area between the Troposphere and the Stratosphere. (put this label on your foldable) • Temperature stops decreasing here. • The altitude of the Tropopause varies according to latitude. At the equator, the Tropopause is at an altitude of about 16 kilometers, while at the poles it is at an altitude of about 9 kilometers. • The jet stream is located just below the Tropopause. • The Jet Stream, known as the “River of Air”, zooms along at 250 mph

20. The Stratosphere • “Strato” means spreading out. • A clear, dry layer of the atmosphere, air contains very little water vapor. • Temperature increases with altitude. • 02 + UV radiation from the sun yields • Jet aircraft and weather balloons fly here Stratosphere 20 to 50 kilometers

21. Ozone • Ozone, an unusual type of oxygen molecule that is relatively abundant in the stratosphere, heats this layer as it absorbs energy from incoming ultraviolet radiation from the Sun. • Ozone Layer is nestled between 15-25 km • Temperature increase in the Stratosphere is caused by the presence of ozone. Ozone absorbs ultraviolet rays from the sun and then releases some of this energy in the form of heat.

22. Temperature and Altitude Stratosphere Write a hypothesis expressing the relationship between altitude and atmosphere temperature. Temperature 0 Altitude Temperature and Altitude are directly related

23. The Stratopause • The area between the Stratosphere and the Mesosphere. • Located at approximately 50 kilometers above Earth’s surface.

24. The Mesosphere • “Meso” means middle. • The Mesosphere extends between about 50 and 85 kilometers above Earth’s surface. • Contains very little ozone, so temperatures again drop with increasing altitude. • Meteors burn up in this layer and are seen as shooting stars on Earth. • It is colder than Antarctica here…cold enough to freeze water vapor into ice clouds. • There are odd types of lightning here…they occur above thunderstorms

25. Temperature Altitude Temperature and Altitude Mesosphere Write a hypothesis expressing the relationship of altitude and atmosphere temperature. 0 Temperature and Altitude are indirectly related

26. The Mesopause • The area between the Mesosphere and the Thermosphere. • Located approximately 90 kilometers above Earth’s surface.

27. The Thermosphere • “Thermo” means heat. • The atmosphere at this great altitude is extremely thin, but the few molecules and atoms present receive such intense solar radiation that temperatures can rise above 1000°C. • The Thermosphere is separated into layers of different gases, with heavier gases in the lower levels and lighter gases in the higher layers. • No well defined upper limit. Thermosphere – from 85km – 600km.

28. The Thermosphere • This is where the space shuttles flew and where the International Space Station orbits Earth. This is also the layer where the auroras occur. • The lowest layer is composed primarily of nitrogen molecules. • Next, a layer of oxygen reaches to about 1000 kilometers. • Above that is a layer of helium that extends to about 2400 kilometers. • Finally, a layer of hydrogen thins out into space. 2400 kilometers = 1488 miles

29. Temperature and Altitude Thermosphere Write a hypothesis expressing the relationship between altitude and atmosphere temperature. Temperature 0 Altitude Temperature and Altitude are directly related

30. The Ionosphere • The portion of the Thermosphere between about 90 and 500 kilometers above the Earth is also called the Ionosphere. • Why? Because the air there is highly ionized. • These ions are formed when ultraviolet rays knock electrons off oxygen and nitrogen molecules and oxygen atoms.

31. The Ionosphere • The Ionosphere is affected by solar events. Huge eruptions associated with sunspots send out large amounts of radiation and ionized particles. • Because the sun’s particles are electrically charged, they are deflected by Earth’s magnetic field to the North and South poles. • The ionized particles sometimes interact with air molecules to form auroras.

32. Exosphere • “Exo” means outer – it is the outermost layer • Extends from 600 km – 10,000km (375 miles – 6,200 miles) • Satellites orbit earth here • The atmosphere merges into space • Hydrogen and Helium are the prime components

33. Magnetosphere • The Earth's magnetic field reaches 36,000 miles into space. • The magnetosphere prevents most of the particles from the sun, carried in solar wind, from hitting the Earth.

34. http://science.howstuffworks.com/environmental/29269-100-greatest-discoveries-earths-atmospheric-layers-video.htmhttp://science.howstuffworks.com/environmental/29269-100-greatest-discoveries-earths-atmospheric-layers-video.htm

35. Aurora Borealis AKA Northern Lights YouTube - Aurora Borealis

36. Review • Name and describe 4 factors that effect the atmosphere. • Name and describe two factors that effect the heating of the atmosphere. • Describe how energy is absorbed and emitted by ozone molecules. • Explain heat “trapped” in the atmosphere. • Describe how the atmosphere pressure changes as the elevation above sea level increases.

37. Review 6. Describe how atmosphere temperature changes as the elevation above the earth surface increases. 7. Explain why most of the weather occurs in the troposphere. 8. Explain why the temperature increases in the stratosphere as altitude increases. 9. Explain why the atmosphere temperature range is greatest in the northern hemisphere as compared to the southern hemisphere. 10. Describe the impact that Earth’s gravity has on the atmosphere.