Homework 1 Key

  1. The lithosphere is the rocky, spherical mass of the earth. It contains most of the mass of the earth-atmosphere.
  2. Volcanic outgassing gave rise to most of the gases in the earth's atmosphere. The main exception is oxygen, which was produced by photosynthesis.
  3. A gas is a "constant constituent" of the atmosphere when its concentration or abundance does not vary with respect to height, location, or time.
  4. Nitrogen, oxygen, argon, neon.
  5. "Constantconstituents" of the atmosphere CAN have sources and sinks, as long as these sources and sinks are in dynamic equilibrium. Oxygen is a good example: the source of oxygen is photosynthesis in plants. The sink of oxygen is primarily animal respiration. These processes are in dynamic equilibrium, and the overall concentration of oxygen doesn't change.
  6. Aerosols are small solids or liquids that are suspended in the atmosphere. Common examples include dust, pollen, ash, salt, clay, etc.
  7. Ozone is important because it absorbs ultraviolet radiation from the sun, which is extremely harmful to all living things. The ozone layer is found in the stratosphere. In the troposphere, ozone is a pollutant.