test 2 Flashcards
How much freshwater is present on earth?
2.78% (Most of that is ice and glaciers)
What is deposition? sublimation?
deposition: water vapor to ice
sublimation: ice to water vapor
What is humidity?
water vapor in the atmosphere.
what is an air parcel?
an air sample taken from the atmosphere
what are the physical controls on absolute humidity (3)
changes in air volume associated with air convection, air subsidence, and surface temperature changes
maximum specific humidity
the warmer the temperature, the greater capacity for the air to hold moisture
Vapor pressure
the increase in air pressure due to water vapor in the atmosphere..because of this, vapor pressure=high amounts of water vapor in the air
saturation vapor pressure
this is the maximum amount of water that can be present in the atmosphere before condensation starts taking place
Saturation point
This is reached when the actual vapor pressure and saturation vapor pressure are the same. In other words, when e=es relative humidity is 100%
what is dew point temperature
refers to the lowest temperature that can be reached before condensation takes place
What would maximize the chance of getting dew in the morning?
- strong radiational cooling..meaning the sky must be clear and the wind needs to be calm.
- moist air at sunset
When would you get dew vs frost?
dew: saturation is above freezing point
frost: saturation happens below the freezing point
foreign objects attracting water vapor at the surface
grass blades, twigs, leaves
Dry haze
this occurs because of pollution and stable weather conditions
wet haze (damp)
frequently observed at seashores. consists of super small water droplets in the air
fog
forms by cooling or evaporation and mixing
Radiation fog
More common in late fall and winter. Produced by earths radiational cooling.
ingrediants:
- Long clear night to allow a strong ground emission of LW
- A considerable amount of moisture in the air (at sunset)
- Calm to light wind
- A terrain which allows cold air to drain downhill (i.e., valley fog)
Advection fog
caused by the transport of warm moist air over cooler surfaces. these happen a lot on the pacific coast during the summer
Upslope fog
happens because moist warm air travels up an elevated area. JUst like advection and radiational fog, cooling is taking place
Evaportion fog (mixing)
This happens during late fall when an inland lake is warmer than a cold air mass coming from north
when e>es ….?
fog takes place
what is …what is es?
e=actual vapor pressure
es= saturation vapor pressure (the max amount of water vapor that can be held in the air)
when is fog considered dense?
visibility has to be greater than .25 miles
Clouds based on height?
cumuilform
Clouds based on form?
stratiform
What are the 3 high clouds?
Cirrus, Cirrocumulus, Cirrostratus
What are the 2 middle clouds?
Altostratus, Altocumulus,
Cirrus clouds. What is their composition? Altitude? precipitation? characteristics?
composition: ice crystals
altitude: 16,000-43, 000 feet
prec: none reaching the ground
Characteristics: These clouds indicate the direction that the wind is blowing. They usually come with fair weather but indicate the weather could change in 24-48 hours
(high cloud)
Cirrocumulus. Composition? Altitude? precipitation? characteristics?
composition: ice crystals
altitude: 16,000-43,000 feet
prec: none reaching the ground
Characteristics: Indicates the presence of warm air. Weather could be changing within the next 24-48 hours
(high cloud)
Cirrostratus. Composition? Altitude? precipitation? characteristics?
composition: ice crystals
altitude: 16,000-43,000 feet
prec: none reaching the ground
Characteristics: indicates rain within the next 12-24 hours. (especially if halo is seen around the sun)
(high cloud)
What do all high clouds have in common?
made up of ice crystals, 16,000-43,000 feet. no precipitation reaching the ground
Altostratus. Composition? Altitude? precipitation? characteristics?
c: water
a: 6,500-23,000 feet
p: none reaching the ground
characteristics: associated with an incoming warm air mass over the region. If the cloud gets thicker, it indicates that it is getting closer to the ground and rain will take place within 6-12 hours
(middle cloud)
Altocumulus. Composition? Altitude? precipitation? characteristics?
c: water
a: 6,500-23,000 feet
p: none reaching the ground
characteristics: associated with an incoming warm front of air over a region. indicates that there could be thunderstorms in the afternoon if the clouds are seen in the morning
(middle cloud)