Introduction to Geography

1. Introduction to Geography Arthur Getis, Judith Getis, & Jerome D. Fellmann

2. Physical Geography:Weather & Climate Chapter 4

3. Overview • Air Temperature • Air Pressure & Winds • Ocean Currents • Moisture in the Atmosphere • Climate • Climate Regions • Climate Change

4. Air Temperature • Solar energy • Insolation • Sun angle • Number of daylight hours • Amount of water vapor • Cloud cover • Land vs. water • Elevation above sea level • Degree & direction of air movement

5. Earth inclination • Axis of the earth tilts at ≈ 23.5° • Rotation once every 24 hours • 21 June / summer solstice • Vertical rays of the sun at 23.5 ° N • Tropic of Cancer • Northern hemisphere tilted towards the sun • 21 December / winter solstice • Vertical rays of the sun at 23.5 ° S • Tropic of Cancer • Equinoxes on March 21 & September 21

6. Reflection & Reradiation • Clouds & light surfaces reflect energy • Reradiation also contributes to lost energy • Water stores more energy than land • Land heats & cools more rapidly • Water heats & cools more slowly

7. The Lapse Rate • 6.4°C per 1000 meters • 3.5°F per 1000 feet • Temperature inversions • Cooler air trapped below warmer air • Can contribute to smog problems

8. Air Pressure & Winds • Air pressure is higher near the earth’s surface • Pressure measured by a barometer • Pressure gradient forces air to blow from high to low pressure areas • Convection • Warm air rises • Cool air sinks

9. Land & sea breezes • Warmer air over land replaced by cooler air over water • Mountain & valley breezes • Cooler air in mountains sinks into valley (often at night) • Warmer air in valleys rises into mountains (often during the day) • Coriolis effect • Wind veers towards the right in the Northern Hemisphere and to the left in the Southern Hemisphere

10. Global Air-Circulation Pattern • Equatorial low pressure • Northeast trades • Westerlies • Subpolar low • Polar easterlies • Polar high

11. Ocean Currents • Roughly corresponds to global wind direction patterns • Differences in water density also cause movement • Coriolis effect • Landmasses are a barrier to currents

12. Moisture in the Atmosphere • Precipitation • Rain, sleet, snow, or hail • Supersaturation leads to droplets if condensation nuclei are present • Relative humidity

13. Types of Precipitation • Convectional precipitation • Orographic precipitation • Cyclonic, or frontal precipitation • Air masses

14. Storms • Midlatitude cyclones • Hurricanes • Typhoons • Blizzards • Tornadoes

15. Climate • A generalization based on daily & seasonal weather conditions

16. Soil Formation • Geology • Climate • Topography • Biology • Time

17. Soil Horizons • O-horizon • A-horizon • E-horizon • B-horizon • C-horizon • R-horizon

18. Soil Properties • Composition • Organic & inorganic • Texture • Proportion of sand, silt, & clay • Structure • Size, shape, and alignments of clumps • Nutrients • Acidity or alkalinity

19. Natural Vegetation • Succession • Natural Vegetation Regions • Tropical rain forest • Mediterranean or chaparral • Semidesert • Desert • Prairie / steppe • Deciduous woodlands • Coniferous woodlands • Tundra

20. Climate Classification • Köppen Climate Types • A • B • C • D • E • H

21. Tropical Climates (A) • Tropical Rain Forest (Af) • Savanna (Aw,Am)

22. Dryland Climates • Hot Deserts (BWh) • Midlatitude Deserts & Semideserts (BWk, BS) • Steppe

23. Humid Midlatitude Climates • Mediterranean (Cs) • Cold, wet winters & dry, hot summers • Humid Subtropical (Cfa) • Marine West Coast (Cfb) • Humid Continental (Dfa,Dfb)

24. Subarctic & Arctic Climates • E • Tundra

25. Climate Change • Long cycles • Quicker changes • Small changes in upper-air wind movements • Volcanic eruptions • Human activity