1. Thermal Response of Climate System
Current Weather and News
Heat Transfer Processes
Latent Heat Transfer
Heating Imbalances
For Next Class: Read rest of Chapter 4
Reminder: Lab will meet next week

2. Heat Transfer Processes
What are the four major heat transfer processes?

3. Heat Transfer Processes
Radiation
Both a form of energy and a means of energy transfer
Radiational heating: object absorbs radiation at a greater rate than it emits radiation
Internal energy increases, temperature rises
Radiational cooling: object emits radiation at a greater rate than it absorbs radiation
Internal energy decreases, temperature drops
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4. Conduction
Conduction: the transfer of kinetic energy of atoms or molecules via collisions between neighboring atoms or molecules
Heat Conductivity: the ratio of the rate of heat transport across an area to the temperature gradient
Substances with a higher heat conductivity have greater rates of heat transport
Solids are better conductors than liquids, liquids are better conductors than gases
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5. Convection
Convection: the vertical transport of heat within a fluid via motions of the fluid itself
Generally only occurs in liquids or gases (fluids)
Convection in the atmosphere consequence of differences in air density
Advection is the horizontal transport of heat
Sensible Heating is the combination of conduction and convection
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6. Latent Heat Transfer Phase Changes of Water
Water occurs naturally in all three phases (solid, liquid, gas)
Depending on phase changes, either absorbs or releases heat to or from environment
Latent heat: quantity of heat involved in phase changes of water
Latent heating: the transport of heat from one location to another as a consequence of changes in the phase of water
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7. Heat Imbalance: Atmosphere vs. Earth’s Surface
Latent Heating
Latent heat of fusion: amount of heat required to convert a solid at its melting point to a liquid without a change in temperature
Latent heat of vaporization: amount of heat required to convert a liquid to a gas without a change in temperature
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8. Latent Heat Transfer Phase Changes of Water
Heat absorbed from environment during changes to higher energy states
melting, evaporation, sublimation
Heat released to environment during changes to lower energy states
freezing, condensation, deposition
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9. 680 cal/g required
80 cal/g required
cal/g required
80 cal/g released
cal/g released
680 cal/g released

10. Land–Water Heating Differences
Figure 5.7

11. Thermal Response and Specific Heat
Specific Heat: amount of heat that will raise the temperature of 1 gram of a substance by 1 Celsius degree
Measured relative to liquid water
Water has the greatest specific heat of any naturally occurring substance
Variation in specific heat from one substance to another implies that different materials have different capacities for storing internal energy
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13. Thermal Response and Specific Heat
Maritime and Continental Climates
Maritime climates: immediately downwind of the ocean, and experience much less contrast between average winter and summer temperature
Continental Climates: well inland, experience a much greater contrast between winter and summer temperature
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14. Heat Imbalance: Atmosphere vs. Earth’s Surface
Sensible Heating
The Bowen Ratio compares how heat at the Earth’s surface is divided between sensible heating and latent heating
Varies from one place to another
Depends on amount of surface moisture
Surface energy budget through the course of a year
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15. Bowen Ratio Bowen ratio = (sensible heating)/(latent heating)
High Bowen ratio implies more sensible heating than latent heating (i.e., deserts)
Low Bowen ratio implies more latent heating than sensible heating (i.e., oceans or water bodies)

16. Heat Imbalance: Atmosphere vs. Earth’s Surface
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