physical science

  1. Water phases transition
    to change from one state to another; heat must be absorbed or released.

    - water, ice, and water vapor
  2. Saturation
    -balance between water vapor molecules leaving the surface and those returning to the surface.
  3. Relative humidity
    - ratio of air's actual water vapor content compared with the amount of water vapor required for saturation at that temperature- and pressure
  4. Dew point temperature
    • -temperature needed to cool air to reach saturation
    • - causes water vapor to condense forming
    • -dew, fog, or cloud formation
  5. variations in temp and relative humidity
    - increasing temps: lower relative humidity

    -decreasing temps: higher relative humidity
  6. Dew point is temperature of saturation...
    -high dew point temp: moist air

    - low dew point temp: dry air
  7. 4 lifting mechanisms that lifts air
    - Orographic lifting

    - frontal wedging

    - convergence

    - localized convective lifitng
  8. (mechanisms that causes air to rise) Orographic lifting
    -air is forced to rise over a mountain

    • - adiabatic cooling generates clouds, precipitation
    • -leeward side of it, rainshadow desert
  9. (mechanisms that causes air to rise) Frontal wedging
    • - cool, dense air acts as a barrier to warm, less dense air.
    • -forces warm air to rise, typical in North America
  10. (mechanisms that causes air to rise) Convergence
    • - air converges from more than 1 direction
    • -forces air upward

    • - change in surface texture can "pile up" air
    • -ocean wind converging onto land
    • -rougher land forces the air to converge
  11. (mechanisms that causes air to rise) Localized convective lifting
    • -unequal surface heat causes localized pockets of air to rise
    • -creates thermals
  12. stable air vs unstable air
    • -stable air resists vertical displacement
    • - cooler, denser than surrounding air
    • -wants to sink

    • - unstable air
    • - warmer air, less dense than surrounding air
    • -tendency to rise
  13. dry adiabatic rate
    - unsaturated air

    • -rising air expands and cools
    • -10 C per 1000 meters
    • -descending air is compressed and warms
    • -10 C per 1000 meters
  14. Wet adiabatic rate
    • - commences at condensation level
    • - air has reached the dew point

    -condensation occurring, latent heat is liberated

    • -heat is released as water condenses
    • - 5-9 C per 1000 m
  15. 3 different forms of clouds


  16. (forms of clouds) Cirrus
    high, white, thin
  17. (forms of clouds) Cumulus
    globular, individual cloud masses
  18. (forms of clouds) Stratus
    sheets or layers that cover much of the sky
  19. (types of clouds) High clouds
    -above 6000 meters

    • -thin, white, made of ice crystals
    • low temps, little water vapor

    - cirrus
  20. (types of clouds) middle clouds
    -2000 to 6000 meters

    -infrequent light snow or drizzle

  21. (types of clouds) low clouds
    -below 2000 meters

    -stable conditions, produces precipitation
  22. 3 types of fogs
    - advection fog

    - radiation fog

    - upslope fog
  23. (fog types) Advection fog
    -warm, moist air moves over a cool surface
  24. (fog types) Radiation fog
    - earth's surface cools rapidly

    - forms during cool, clear, calm nights
  25. (fog types) Upslope fog
    humid air moves up a slope
  26. 2 evaporation fogs
    fogs resulting from addition of water vapor

    -steam fog

    -precipitation fog
  27. (evaporation fogs) Steam fog
    - cool air moves over warm water, moisture added to air

    -water has a steaming appearance
  28. (evaporation fogs) Precipitation fog
    -frontal wedging when warm air lifted over colder air

    -rain evaporates to form fog
  29. latent heat
    -energy released or absorbed during a change of state
  30. Forms of precipitation
    - Hail


    -rain or drizzle


    -sleet and glaze
  31. (forms of precipitation) Hail
    - they come from large cumulnonimbus clouds

    -updrafts that occur carry the ice higher, the higher its carried the bigger hail
  32. (forms of precipitation) Rime
    - deposit of ice crystals from freezing of supercooled fog or cloud droplets on surfaces below freezing
  33. (forms of precipitation) Rain or Drizzle
    - typically in nimbostratus clouds

    drizzle: stratus or nimbostratus clouds
  34. (forms of precipitation) Snow
    precipitation in form of ice crystals

    size, shape vary by temps

    • -Warmer temps: composite snowflakes
    • -heavy, high moisture content

    • - Cold temps: low moisture content
    • -light fluffy snow
    • - 6 sided crystals
  35. (forms of precipitation) Sleet
    -occurs when warmer air overlies colder air

    -rain freezes as it falls
  36. (forms of precipitation) Glaze
    -subfreezing air near ground

    -raindrops become supercooled during fall thru cold air

    -turn to ice upon colliding with solid objects
Card Set
physical science
cloud development and forms