Chapter 1: The Earth’s Atmosphere

1. Chapter 1: The Earth’s Atmosphere • Overview of the Earth’s atmosphere • Vertical structure of the atmosphere • Weather and climate

2. Overview of the Earth’s Atmosphere • The atmosphere, when scaled to • the size of an apple, is no thicker • than the skin on an apple • Water vapor molecules are invisible: • clouds; • condensation; • evaporation Fig.1.2

3. Composition of the Atmosphere • permanent gases • variable gases • roles of nitrogen and oxygen • role of water vapor Fig. 1.4

4. Table 1-1, p. 3

5. 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.”

6. FIGURE 1.3 The main components of the atmospheric carbon dioxide cycle. The gray lines show processes that put carbon dioxide into the atmosphere, whereas the red lines show processes that remove carbon dioxide from the atmosphere. Stepped Art Fig. 1-3, p. 4

7. 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.

8. 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

9. A Brief Look at Air Pressure and Air Density • air density • air pressure • sea-level pressure • Baseballs travel farther in higher-altitude air (Denver)than they do in lower-altitude air. • Surface pressure: 1013 mb = 1013 hPa = 29.92 in.Hg

10. Fig. 1-7, p. 8

11. Fig. 1-8, p. 9

12. Layers of the Atmosphere • vertical temperature profile • Troposphere lapse rate: 6.5degC/1km; temperature inversion • stratosphere • mesosphere • thermosphere

13. 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.

14. Fig. 1-11, p. 13

15. Weather and Climate • Satellites • Radar • Radiosonde • Aircraft • Weather station

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

17. Climate • average weather • extremes

18. 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.

19. 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.

20. Fig. 1.17 Fig. 1.15

21. 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.

22. Fig. 1-13, p. 17

23. 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.

24. Fig. 1-16, p. 19

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