Monday, January 11, 2012
Lecture 1 and 2 Notes
Lecture 1-2: January 11 and 13, 2012
• Source: adding more
• Store: storage for later
• Sink: using it up
The Earth’s Climate
• Causes (External Forcing)
• Changes in Plate Tectonics
• Changes in Earth’s Orbit
• Changes in sun’s strength
• Climate System (internal interactions)
• Atmosphere
• Vegetation
• Ice
• Ocean
• Land surface
• Climate Variations (internal responses)
• Change in Atmosphere
• Changes in ice
• Changes in vegetation
• Changes in ocean
• Changes in land surface
• Wien’s Law: Peak radiation (wavelength) decreases as temperature increases
• Stefan-Boltzmann Law: hotter objects emit more radiation
• Incoming solar radiation is less for a non-rotating dusk than for a rotating sphere
• Radiation Input: solar radiation to Earth; concentrated in shorter wavelengths: ultraviolet visible and shortwave infrared
• Radiation Output: Earth’s infrared emission to space
• Albedo: Reflecting power of a surface; how much sunlight is reflected
• Fresh snow: 80-95%
• Water bodies: 10-60%
• Grass: 25-30%
• Crops, grassland: 10-20%
• Forests: 10-20%
• Earth Average: 31%
Energy Balance: Green House Effect
Composition of the Earth’s Atmosphere
Why are the Tropics warmer?
• More concentrated solar radiation
• Rays are more diffused at poles
• Rays arrive parallel to Earth at the equator
Vertical Structure of the Atmosphere
• Thermosphere (>80 km)
• Masosphere (50-80 km)
• Stratosphere (12-50 km); stable, ozone, volcanic particles
• Troposphere (0-12 km); unstable
• Polar Cell, Ferrel Cell, Hadley Cell, Hadley Cell, Ferrerl Cell, Polar Cell
• Air sinks over the northern subtropical desert zone
• Tropical air flows north of the Northern Hadley Cell, dry desert air flows south
• Warm, moist air rises at the intertropical convergence zone, near the equator
• Tropical air carries heat south of the Southern Hadley Cell
• Air sinks over the southern subtropical desert zone
Pressure Gradient, Coriolis, and Winds
• High pressure to Low pressure
• Or high pressure to Coriolis deflection in northern or southern hemisphere