Lecture 8: The atmosphere and solar radiation
I. Introduction: Extreme Climatic Events (Table 9-1)
A. Not unusual over geological time
B. Costly
C. Related to atmospheric activities
D. Uncertain if recently increasing in frequency?
E. “ The debate over whether or not there is a global warming signal is now over,
At least for rational people” Tim Barnett, Scripps Inst. Of Oceanography
(April 2005, Science)
II. Characteristics of our Atmosphere (Figs. 9-3, 9-4)
A. Review: Boundaries, Age, Composition
B. Feedbacks between Biota & Atmosphere
C. Atmospheric composition: Gases
D. Importance of water
1. amount in atm varies spatially
2. cloud formation
3. most powerful greenhouse gas
4. Transports heat from equator to poles
5. Condensation predominates at high latitudes
III. Structure and characteristics of the atmosphere
A. . Troposphere
1. Boundaries
2. Tropopause
3. Temperature gradient
4. Pressure
5. Concentration
6. Mixing
B. Stratosphere
1. Lower boundary 10-50 km
2. Ozone production
3. Temperature gradient
4. Mixing minimal
5. Water content very low
C. Mesosphere and Thermosphere
IV. Climate and weather
A. Introduction
1. Climate
2. Weather
B. Solar energy: absorption and emission
1. Magnitude
2. Overview of Solar Radiation
3. Sun’s is radiant energy or radiation
4. Radiant energy is converted to thermal energy after its absorbed
5. The conversion = change in wavelength
6. Demonstration: Flame test
7. How is energy transformed?
Electron falling from high to low energy levels & emitting light
Long wavelength, low energy
Short wavelength, high energy
High
energy
Low
energy
High
energy
Rings are Different Energy Levels
Low
energy
8. Sun’s vs Earth’s energy (Similar to box 9-2)
C. Fate of incoming solar energy
D. The greenhouse effect
E. The greenhouse effect on other planets