Chapter 17: Moisture, Clouds, and Precipitation Flashcards
The three states of matter in water
- Solid (ice)
- Liquid (water)
- Gas (water vapor)
When water changes states, what happens to the heat?
It is Absorbed or Released
How is heat energy measured?
- In calories.
1 calorie is the heat necessary to raise temp
What is latent heat?
*Stored or hidden heat
when water changes, heat exchanges between water and its surroundings
The process where liquid water is changed into gas (water vapor) is called what?
Evaporation
“latent heat of vaporization”
The process where water vapor (gas) is changed to liquid water is called what?
Condensation
“latent heat of condensation”
The process where solid ice is changed to liquid water is called what?
Melting
“latent heat of melting”
The process of water being changed to a solid (ice) is called what?
Freezing
“latent heat of fusion”
The process of a solid changing directly to a gas is called what?
Sublimation
EX: ice cubes shrinking in freezer
When water vapor is deposited into ice is is called what?
Deposition
Water vapor (gas) is changed directly to a solid EX: frost is a freezer
Humidity is what?
The amount of water vapor in the air.
Saturated air is air filled with water vapor to callosity
Relative Humidity (R.H.)
Capacity is temp dependent
Water vapor adds pressure to the air- this is called vapor pressure
Condensation (dew) occurs when?
When water vapor is changed to a liquid.
Adiabatic temperature occurs when?
- Air is compressed.
* Air will warm as it is compressed (EX: pumping up bike tire) - Air expands.
* Air will cool as it expands (EX: air escaping bike tire)
The four processes that Lift air are?
- Orographic Lifting
- Frontal Wedging
- Convergence
- Localized Convective Lifting
What is Orographic Lift?
Elevated terrains act as barriers to the flow of air & force air to rise up.
EX: Atacama Dessert in Chile..driest place in the world
What is Frontal Wedging?
Masses of warm & cold air collide to produce a front.
Where cooler, dense air acts as a barrier to warm air and forces it to rise
What is Convergence?
Air flowing together int he lower atmosphere.
Converges and rises as a result in contrasting air masses that are forced to rise.
What is Localized Convective Lifting?
Occurs when unequal surface heating causes pockets of air to rise
Air Stability depends on?
- Type of clouds that develop
* Intensity of the precipitation
What is Stable Air?
- Resists vertical displacement
- Cooler than surrounding air
- Denser than surround air wants to sink
Water vapor in the air changes to a liquid and forms dew, fog, or clouds is called what?
Condensation
Condensation surfaces in the atmosphere are called what?
Condensation nuclei: dust smoke salt crystals ect.
Visible aggregates of millions of minute of minute droplets of water or tiny ice crystals, are called what?
Clouds!
Two cloud classifications based on form and height?
- Form:
2. Height in the Atmosphere
Form in clouds contain what?
- Cirrus- high, white, thin clouds
* Cumulus- cloud masses associated w/ fair weather
Height in the Atmosphere have what type of clouds?
- High clouds- all made of ice crystals
- Middle clouds- has “alto” prefix
- Low clouds- below 2,000 meters
What type of clouds produce rain showers and thunderstorms?
Cumulonimbus
What is the Collision- Coalescence Process?
**Droplets collide and coalesce w/ other droplets
- Warm clouds
- fewer, larger condensation nuclei are present, this allows large droplets to form.
What is rain and drizzle?
Rain- droplets are at least 0.5 mill
Drizzle- droplets are less than 0.5 mill
What is snow?
Precip. falling in a form of ice crystals or aggregates of ice crystals
What is Sleet vs. Glaze (aka freezing rain)?
Sleet- (wintertime phenomenon)
Occurs: warmer air overlies colder air.
Rain freezes as it falls to produce sleet
Glaze/ freezing rain-
impact w/ a solid surface causes freezing, but the water droplets are liquid as they fall.
What is hail and how does it form?
Hail- hard, rounded pellets of irregular ice.
Formation:
occurs in large cumulonimbus clouds w/ violent updrafts & downdrafts
**Hail falls when ice pellets are too heavy
What is the easiest form of precipitation to measure?
Rain with a rain gauge!
