NATS101 Section 4 Web Site: atmo.arizona/courses/fall09/nats101s4/index.html

1. NATS101 Section 4 Web Site: • http://www.atmo.arizona.edu/courses/fall09/nats101s4/index.html • How to find this site? • Go to http://www.atmo.arizona.edu • Click courses • Click NATS101 - Zeng • Bookmark this site • Check the website frequently for new announcements • “Refresh (Reload)” the page every time you visit, to • make sure it displays the latest information

2. Chapter 1: The Earth’s Atmosphere • Overview of the Earth’s atmosphere • Vertical structure of the atmosphere • Weather and climate Q: You can live for a few minutes only: a) without air b) without water c) without food

3. Overview of the Earth’s Atmosphere • when the earth is scaled to the size • of an apple, 99% of atmosphere is • no thicker than the skin on an apple • Water vapor molecules are invisible: • clouds; • sink: condensation/deposition • source: evaporation/sublimation • transpiration Fig.1.2

4. Composition of the Atmosphere • permanent gases • Nitrogen source: decaying of plant and animal matter sink: soil bacteria; ocean plankton • Oxygen source: plant photosynthesis (sun + CO2 + H2O lead to sugar and O2) sink: organic matter decay breathing (take in O2, release CO2)

5. Q: which is the most important greenhouse gas in the atmosphere? a) water vapor; b) carbon dioxide; c) methane, d) ozone 380 ppm = 380/106 = 380 * 10-4/102 = 0.038% Table 1-1, p. 3

6. Composition of the Atmosphere • Carbon dioxide and the greenhouse gases • ozone • aerosols • pollutants • Ozone at high altitudes (stratosphere) is “good”;ozone at low altitudes (troposphere) is “bad.” Fig. 1.4

7. Q: List three sources and two sinks of CO2 in the atmosphere Stepped Art Fig. 1-3, p. 4

8. The Early Atmosphere • the first atmosphere: hydrogen, helium • outgassing and the second atmosphere water vapor, carbon dioxide, nitrogen • evolution of the atmosphere: carbon dioxide and oxygen • The evolution of life and the atmosphere are closely linked.

9. Vertical Structure of the Earth’s Atmosphere Radiosonde launched twice a day to measure temperature, humidity, wind, and pressure of the lowest 30 km above surface Q: where is the balloon launched in Tucson? a) airport; b) Mt. Lemmon, c) UA campus

10. A Brief Look at Air Pressure and Air Density • air density: mass per unit volume • air pressure: air weight above a level • sea-level pressure • Surface pressure: 1013 mb = 1013 hPa = 29.92 in.Hg Q: Baseballs travel farther in higher-altitude air (Denver) than they do in lower-altitude air: true or false?

11. Fig. 1-7, p. 8

12. Q: what is the percentage of O2 at the top of Mt. Everest compared with sea level? a) 13% b) 23% c) 33% d) 43% Fig. 1-8, p. 9

13. Layers of the Atmosphere • vertical temperature profile • Troposphere lapse rate: 6.5degC/1km; temperature inversion • Stratosphere O3 absorption • mesosphere • Thermosphere O2 absorption

14. The Ionosphere • electrified regions of the atmosphere • D, E and F regions • radio waves • When the radio was invented by G. Marconi in the early 20th century, it was not known how radio waves traveled long distances through the atmosphere.

15. Fig. 1-11, p. 13

16. Weather and Climate • Satellites • Radar • Radiosonde • Aircraft • Weather station • See ATMO web site

17. Elements of Weather • air temperature • air pressure • humidity • clouds • precipitation • visibility • wind • Certain weather elements, likeclouds, visibility and wind, areof particular interest to pilots.

18. Climate • average weather • extremes Q: What is the difference between weather and climate?

19. A Satellite’s View of the Weather • geostationary satellites • Atmospheric observation from satellites was an important technological development in meteorology. Otherimportant developments include computers, internet, and Doppler radar.

20. Storms of all Sizes • midlatitude cyclonic storms • hurricanes and tropical storms • thunderstorms • tornadoes • Storms are very exciting, but they also play an important role in moving heat and moisture around throughout the atmosphere.

21. Fig. 1.17 Fig. 1.15

22. A Look at a Weather Map • wind speed and direction • cyclones and anticyclones • fronts • Wind direction is defined in the opposite way asocean currents: a southerly current means water is moving towards the south.

23. Q: What is the wind direction in Chicago? a) southerly, b) northerly, c) easterly, d) westerly Fig. 1-13, p. 17

24. Weather and Climate in our Lives • wind chill, frostbite and hypothermia • heat exhaustion and heat stroke • cold spells, dry spells and heat waves • severe thunderstorms and flash floods • The mathematical formula for determining the windchill temperature has recently been revised due to newexperiments.

25. Fig. 1-16, p. 19

26. Fig. 1.19 Fig. 1-18, p. 20