1. Earth’s Atmosphere

2. Relevance? Air we breathe Screens against meteor impact Absorbs UV radiation Bounces radio waves off the ionosphere

3. How much atmosphere? Thinner with increasing altitude, with no definite boundary. The Kármán line, at 100 km (62 mi), or 1.57% of Earth's radius, is often used as the border between the atmosphere and outer space.

4. Structure Thermosphere: absorb solar radiation (gets warmer as get higher) Stratosphere: gets warmer as get higher low turbulence ozone absorbs UVA, UVB (higher) ozone produced (lower) Troposhere: 80% of the mass 99% of water vapor gets colder as get higher; heated from below Mesosphere: gets colder as get higher

5. colder as move higher due to radiation; CO2 radiation of energy extends for 11 miles up warmer as move higher due to ozone absorption of energy (thus, cools)

6. Vertical profile of atmosphere (and temperature)

7. Composition of the Atmosphere permanent gases: 78% N 2, 21% O 2, 0.93% Ar trace gases: water vapor: 0.01% at poles, 4% in tropics carbon dioxide:.039% methane, ozone, CFCs aerosols

9. 1952 car driving in thick smog in London Aerial photos of a street of chimneys in London. The Great Smog of 1952 in London, England

10. Smog in China today Cars in Beijing in smog Oct 10, 2014 Tiananmen Square in smog Oct 10, 2014

12. Key Air Pollutants Particulate matter Ozone at ground level – respiratory distress primary: NOx, SOx, CH 4 secondary: ozone, nitric acid, sulfuric acid... lead, mercury CO 2, CO Radon-222 (decays into solid Po-210) Indoor air pollution – burning biomass

13. Compare Reduction in Ground-Level Ozone Emissions from 1980 – 1990 - 2000 Ozone at ground level is a pollutant

14. Changes in Ozone Layer at Antarctica by Year Ozone at high altitude blocks UVA, UVB radiation and is crucial for humans

15. Power Plant Emissions of Sulphur Dioxide & Nitrous Oxide, Feb 2013 Emissions of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) from the electric power sector in 2012 declined to their lowest level since the passage of the Clean Air Act Amendments of 1990

16. Acid Deposition SO 2 and NO are emitted transformed to H 2 SO 4, HNO 3 deposited by rain and create acidic soil/lakes acidic pH makes metals more soluble: – Ca, Mg leach out of soil – Pb, Hg dissolve in water and accumulate in fish – pH<5.5 in soil damages tree roots and ag Define pH; describe the pH scale.

17. One Third of Air pollution from Lead in San Francisco Originated in Asia

18. Ozone Depletion Stratospheric ozone blocks 95% of UV-A, UV-B Oct/Nov – 40% of ozone over Antarctica missing Moves north to NZ and S Africa and increases UV

19. ChloroFluro Carbons CFCl 3 + electromagnetic radiation → Cl· + ·CFCl 2 Cl· + O 3 → ClO + O 2 : loss of ozone hydrofluorocarbons can be 10,000X more potent than CO 2 for global warming Montreal Protocol of 1987 – phasing out CFCs

20. Clean Air Act (1970) To address dense, visible smog Major revisions in 1977 and 1990 to address acid rain and ozone in stratosphere FOCUS: Reduce particles, ozone, lead, carbon monoxide, nitrogen dioxide and sulfur dioxide + others Does not expire...

21. Economy still grows...

22. Weather is created by.... Heating of Earth causes convection, clouds More solar radiation in tropics, then changes in pressure Winds move from high pressure to low pressure (measure with barometer)

23. Climate – Rain Shadow

24. Climate DEFINE: Weather conditions prevailing in an area, in general, or over a long period (including storms, precipitation, cloud cover, temperature...)

25. Climate Change Climate change is not a political issue and climate change is not a debate. Greenhouse gases: CO 2, H 2 O, CH 4, chlorofluorocarbons (CFCs), N 2 O (nitrous oxides) What is common between these gases?

26. Global Carbon Cycle