Geology 1001/1101

1. Geology 1001/1101 Sec 003 Chris Paola Class 12: climate and glaciation

2. Chapter 10 THE CLIMATE SYSTEM AND GLACIATION

3. Key ideas about climate & glaciation • Much of Minnesota’s landscape has been sculpted by glaciers • Glacial cycles are controlled by variation in Earth’s orbit on time scales of 10,000 – 100,000 yr • Climate  weather; climate is long-term average of weather

4. Climate: planetary controls • Distance from Sun • Albedo (reflectivity or “whiteness”) • Atmosphere (greenhouse effect) • Orbital properties • Plate configuration (mainly due to effect on ocean circulation)

5. Climate: geographic controls • Distance from equator • Average air flow & pressure • Distance to the ocean • Prevailing wind relative to mountains & ocean

6. Cold Hot NOT distance to Sun! 92,900,000 miles 3,900 miles

7. all sunlight that hits Earth’s surface

8. 10% of sunlight spread across 6.5% of sunlit surface at equator, Earth’s surface is almost perpendicular to sunlight, so energy is concentrated in small area

9. 10% of sunlight spread across 6.5% of sunlit surface ~ 150% of average intensity at equator, Earth’s surface is almost perpendicular to sunlight, so energy is concentrated in small area

10. 10% of sunlight spread across 20.5% of sunlit surface 10% of sunlight spread across 6.5% of sunlit surface ~ 150% of average intensity at poles, Earth’s surface slopes away from sunlight, so energy is spread across a greater area

11. 10% of sunlight spread across 20.5% of sunlit surface < 50% of average intensity 10% of sunlight spread across 6.5% of sunlit surface ~ 150% of average intensity at poles, Earth’s surface slopes away from sunlight, so energy is spread across a greater area

12. Cold Hot due to the angle of the Earth’s surface

13. Global air flow determines large-scale rainfall patterns Mars: one cell per hemisphere

14. dry wet dry Earth: 3 cells per hemisphere

20. Energy and power • Energy (work) • Joules • BTUs: 1 BTU = 1055 J • Kilowatt-hour: 1 KWH = 3600000 J • Calorie (food): 1 Cal = 4187 J • Power: energy per time (energy rate) • 1 Joule/sec = 1 Watt • 1 HP = 746 Watt • US energy consumption (power), per capita: 11.4 kW (11,400 Watt)

22. 99% of air mass

23. Importance of the ocean in climate • Heat storage (heat capacity of water >> that of air) • Heat and moisture transport

26. Ocean currents

27. Importance of the ocean in climate • Heat storage (heat capacity of water >> that of air) • Heat and moisture transport now onto the cryosphere…

33. A side note: Ice and sea level

37. El Niño Warm, rising air here  lo pressure  helps maintain the wind pattern

38. El Niño movie

39. Part II: glaciation

41. Movies