Download Dew, fog, clouds handout

Dew, Frost, Fog and Clouds!
Dew Point
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No, it’s not the point of dew…
Humidity of air is determined by the amount of water vapour it has
__________________ amount of water present in a body of air
________________- is the percentage of water vapour in the air
_______________ when the air is 100% saturated it cannot hold
any more water
If air is 50% saturated, how much more water can it hold?
_______________________________________________
What happens when the air gets warmer?
_______________________________________________
Dew
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After sunset, the ground quickly loses a lot of heat it gets in the day.
What does this mean for the air?
__________________________________________________
As the temperature drops, the relative humidity continues to increase
until the air is 100% saturated
 Why would this cause water droplets on the ground?
 ________________________________________________________
________________________________________________________
Fog
 When air close to earth is cooled enough that the dew point has
reached, water vapour begins to condense and forms a low lying cloud
called _______
________________________
 Forms during _______________________________
 When the ground cools in the evening, it cools the air close to ground
level
 As the temperature reaches dew point, water vapour begins to
condense and low lying fog becomes visible
 If the air being cooled has a lot of moisture in it, very thick
____________________________________will form
 Can last for days if the heat of the Sun is not strong enough to raise
the temperature
Advection Fog
 Needs air to be moving horizontally
 Warm, moist air passes over a cool surface like the ocean and the
temperature drops
 What happens if it drops enough
to hit the dew point?
 ___________________________
___________________________
 This type of fog can be blown
inland and cause major travel
problems
Clouds
 Simply condensed water vapour
that consists of water droplets or
ice crystals
 Three main types of clouds:
 High Clouds
 Middle Clouds
 Low Clouds
High
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Clouds
Seen at altitudes of 7000-13000 metres
Mostly made of ice crystals, do not produce precipitation
____________- indicate the arrival of a warm front
__________________- similar to cirrus but have a layered
appearance
 _________________- also layered but are much thicker and may
cover the entire sky
Middle Clouds
 Formed at altitudes from 2000 to 7000 metres
 ________________- white and gray in colour and have a puffy
appearance
 ____________- appear blue-ish gray, never white because of the
high amount of condensed water vapour in the cloud
Low Clouds
 Found at lower altitudes
 ____________________- appear white but may have dark
patches. Not rain clouds.
 ______________- appear gray in colour and have a base that looks
the same across the sky. Do not create heavy precipitation, but a
steady, light drizzle.
 ______________________- layers and dark due to high moisture
content. They can create steady, prolonged precipitation.
________________________
 these clouds are generated by rising air currents and can reach heights
of __________________
 ________________- vertical, white in colour with a dark, flat base.
Rising air currents produce a cauliflower appearance at the top. Can
be transformed into cumulonimbus clouds if it is warm enough… what
are these?
 ___________________- have violent, circulating air currents that
can create massive hail stones. Thunder and lightning are associated
with this type of cloud.
Dew Point
Dew
High Clouds
Cirrus
Altostratus
Cumulus
Absolute
Humidity
Fog
Middle Clouds
Cirrostratus
Stratocumulus
Cumulonimbus
Relative Humidity
Saturation
Radiation Fog
Low Clouds
Cirrocumulus
Stratus
Advection Fog
Vertical Clouds
Altocumulus
Nimbostratus