1. Physical Geography by Alan Arbogast Chapter 5
Global Temperature Patterns
Lawrence McGlinn
Department of Geography
State University of New York - New Paltz

2. Absorbed Radiation
Stored in Earth’s land and water surfaces as sensible heat which can be felt & measured
Stored heat can be released from surface by:
Radiation to atmosphere or to space
Conduction to atmosphere
Evaporation/Latent heat to atmosphere

3. Evaporation/Latent Heat
Liquid water → Water vapor (gas)
Latent Heat – heat energy associated with the changing state of water
Heat absorbed in evaporation
Breaks molecular bonds of liquid
Cannot be felt or measured
Released when condensation occurs

4. Changing State of Water
GAS
LIQUID
SOLID
Deposition
Heat Released
Sublimation
Heat Absorbed
Vaporization
Condensation
Melting
Freezing

5. Reflected Radiation
Depends on surface albedo and angle of incidence (link to animation)
Albedo – % of insolation an object reflects
High – dark surfaces
Low – light surfaces
Angle of incidence – Sun angle
High – little reflectance
Low – high reflectance, esp. water

6. Solar Radiation and Earth’s Surface

7. Solar Radiation and Earth’s Surface

8. Solar Radiation and Earth’s Surface

9. Local Factors Influencing Air Temperature
Urban Effect
Urban Heat Island
Darker surfaces – less reflection
Less forest cover
Less water on surface
Heat from human energy use

10. The Urban Environment

11. Urban Heat Island

12. Global NET R Non-vegetated surfaces lose heat in one of 3 ways:
Latent heat of evaporation – energy released as water changes state
Sensible heat – heat you can feel and measure; convection and conduction
Ground heating and cooling – energy stored during warm periods and released during cool periods

13. Radiation Budgets: Types of Heating
Pasture: Shannon, GA
Desert: Big Bend National Park, TX
Riparian Environment: Rio Grande River, TX

14. Global Radiation Budget
(Balance between incoming and outgoing radiation on Earth)
Major variations in net radiation by latitude
Surplus vs. Deficit
Net Radiation – difference between incoming and outgoing radiation

15. Global Radiation Budget
Seasonal variation in net radiation

16. Daily Insolation
Yearly pattern Variation by latitude

17. Heat vs. Temperature Heat and Temperature are not the same thing
Heat: a form of energy that flows from one system or object to another because the two are at different temperatures
Temperature: a measure of the average kinetic energy (motion) of individual molecules in matter

18. Principal Temperature Controls
Latitude
Altitude
Cloud Cover
Land-Water Heating Differences

19. Latitude and Temperature
Affects insolation
Sun angles
Daylength

20. Altitude Altitude High altitude has greater daily range
High altitude has lower annual average

21. Cloud Cover

22. Land–Water Heating Differences
Evaporation (= latent heat)
Transparency (= penetration of insolation)
Specific heat (differs among objects)
Movement (= vertical mixing)
Ocean currents and sea surface temperatures (= spread of energy spatially)
All this leads to this important concept: Marine vs. continental effects

23. Land–Water Heating Differences
Continental
Marine

24. Land Is Opaque

25. The Gulf Stream

26. Marine and Continental Climates

27. Local Factors Influencing Air Temperature
Maritime vs. Continental Location

28. Annual Range of Surface Temp
Temp range on land vs. temp range on water

29. Earth’s Temperature Patterns
Isotherm and thermal equator
January Temperature Map  
Thermal equator movement southward
More pronounced over large continents
July Temperature Map  
Thermal equator movement northward
Annual Temperature Range Map
Continentality

30. January Temperatures

31. July Temperatures

32. Global Temperature Ranges