Transcript 11.3 Moisture in the Atmosphere

Moisture in the Atmosphere
What makes a Cloud?
1. Moisture
2. Reduction in pressure or
temperature causing
condensation.
3. Condensation nuclei small particles in the
atmosphere around which
cloud droplets can form.
Dust
Salt
Smoke
Cloud Formation
• Orographic lifting occurs when wind
encounters a mountain and the air has no
place to go but up.
• The air expands and
cools resulting in
cloud formation.
Orographic lifting occurring in Maui.
Cloud Formation
• Cloud formation occurs with the collision of
air masses (fronts) of different temperatures.
• As fronts
collide clouds
form
Weather Map
– Warm air rises quickly and forms
cumulonimbus clouds and thunderstorms
(Sometimes tornados)
Stability
– How rapidly any given mass of air cools determines its
stability.
– Stability is the ability of an air mass to resist rising.
–Latent heat is stored energy in water vapor that is
not released to warm the atmosphere until
condensation takes place.
How to Classify Clouds based on
Height
• Cirro – 6000 m or higher
• Alto – 2000m to 6000m
• Strato – below 2000m
How to Classify Clouds based on Shape
• Cirrus – Thin and Wispy
» Latin – hair
• Cumulus – Puffy-flat bottom
» Latin – pile or heap
• Stratus – Sheet like
» Latin – layer
• Nimbus - Rain
» Latin - Cloud
Water Cycle
• The constant movement of water between
the atmosphere and Earth’s surface.
– Evaporation – liquid to gas
– Condensation – formation of water droplettes
– Precipitation- Rain
– (Evapo)transpiration- plants loose water
through stomata
The Water Cycle