Phys. Geo Chapter 6

  1. Water Characteristics (6)
    • 1) High boiling point (100C) and low Freezing pint (0c), allows a lot of liquid water on planet
    • 2) High Heat Capacity(specific Heat), store large amounts of heat, aids in keeping the earths climate moderate.
    • 3) High Heat of Vaporization: water absorbs large quantities of heat when converted to vapor.
    • 4) Solvency: universal solvent, dissolves large amounts of materials
    • 5) High surface Tension: attraction between molecules that causes surface to contract and is responsible for liquid waters capillarity.
    • 6) Expands when freezes: ice has a lower density than water, water freezes from top down which prevents aquatic ecosystems
  2. Distribution of H2O
    • Oceans: 97.2%
    • Fresh water 2.8% (includes ice caps,glaciers, ground water, streams and rivers)
  3. Hydrologic Cycle
    - series of storage areas interconnected by various transfer processes, in which there is a ceaseless interchange of moisture in terms of its geographical location and its physical state.
  4. Evaporation
    • - process by which liquid water is converted to gaseous water vapor.
    • - stored energy and is heat removed from water body: evaporative cooling
    • - amount and rate of evaporation is a function of temperature of air and degree of saturation.
    • - greater the temp, greater chance of evaporation
    • - greater motion in air, quickly dispersed moisture
  5. Condensation
    • process by which water vapor is converted to liquid
    • air must be saturated
    • temperature cools to dew point and water droplets grow and causes clouds
  6. Transpiration
    - transfer of moisture form planet leaves to the atmosphere.
  7. Precipitation
    process in which moisture is removed from ATM
  8. Infiltration
    downward movement of water through the soil layer and regolith.
  9. Initial Abstraction
    portion of the precipitation that does not runoff or infiltrate, short term ponding of water
  10. Runoff
    flow of water from liquid to ocenas by overland flow, streamflow and groundwater flow.
  11. Humidity
    • - amount of water vapor in the air
    • - depends on temperature of the air parcel
  12. Absolute Humidity.
    - mass of water vapor over vol of air
  13. Specific Humidity
    - mass of water vapor over mass of air
  14. Relative Humidity
    • - amount of water vapor over moisture holding capacity
    • - varies with vapor content and temp.
    • - moisture added to ATM, RH goes up
    • - air mass cools then moisture holding capacity goes down therefore RH goes up
  15. Dew Point
    • Dew: condensation of breads of water on relatively cold surfaces
    • Dew point: critical air temperature at which saturation is reached (100% RH)
  16. Adiabatic Process
    - natural cooling of air to dew point returns water vapor from ATM to earths surface
  17. Adiabatic Cooling
    - cooling by expansion in rising air
  18. Adiabatic Warming
    • - warming by contraction in descending air
    • - moisture holding (when it rises) the RH lowers
  19. Clouds
    • - composed of water vapor and supercooled ice
    • - formed when rising air is cooled, reachers LCL and the water vapor turns into clouds.
  20. Unstable air/ Stable air
    • - unstable air rises- clouds
    • - stable air doesn't rise- no clouds
  21. Classification of Clouds (Forms)
    • Forms (appearance)
    • 1) cirriform - high altitude thin wispy clouds
    • 2) Stratiform- real broken up grayish sheets or layers.
    • 3) Cumuliform- narrow tall massive rounded clouds.
  22. Cloud Types (height)
    • High Clouds (above 20,000 ft) : Cirrostratus, Cirrocumulus, Cirrus -- most water is solid
    • Middle Clouds (6,500ft-20,000ft): Altocumulus, altostratus -- puffy layered, liquid water
    • Low Clouds: (below 6,500 ft): Stratocumulus, stratus, nimbostratus(rain)
    • Clouds of vertical development: cumulus, cumulonimbus(rain).
  23. Fog
    • - no physical difference between fog and clouds just the height of the base.
    • - defined as a cloud whose base it at or very near ground level
  24. Radiation Fog
    - A fog produced by condensation near the ground, whose air is cooled to the dew point byy contact with cooler ground.
  25. Advection Fog
    A fog that results when warm, moist air moves horizontally over a cold surface
  26. Orographic (upslope) fog
    A fog caused by adiabatic cooling when humid air is caused to ascend up a slope (like a mountain).
  27. Evaporation Fog
    Fog that results from the addiction of water vapor to cool air that is already near saturation.
Card Set
Phys. Geo Chapter 6
Chapter 6...Atmospheric Moisture/precipitation