1. Clouds & Weather
SOL 6.3 b,c,d,e

2. WHAT CAUSES CLOUDS & WEATHER ON EARTH?
HEAT!
The Earth’s surface is heated unequally.
The Equator receives MOST of the sun’s direct radiation.
The North & South Pole receive very little of the sun’s radiation because they are farther from the sun, and they receive its light at an angle.

3. THE SUN’S HEAT ENERGY MOVES THE AIR!
The sun’s radiation heats the air on Earth’s surface.
That heated air rises, starting a convection current.
As the warm air rises, cool air falls to take its place.

4. THE SUN’S HEAT ENERGY MOVES EARTH’S WATER!
The sun also heats the oceans more at the equator causing water to move away from the equator, causing surface currents, like the Gulf Stream.
The sun’s heat powers the water cycle. It evaporates water all over Earth’s surface!
This movement of the atmosphere and oceans causes our weather.

5. HOW DO CLOUDS FORM? (The water cycle -- of course!)
As bodies of water (oceans, lakes, rivers, etc.) absorb heat energy, the water molecules rise and expand (move apart).
The water BECOMES A GAS (water vapor) We call this EVAPORATION.
The water vapor cools in the upper atmosphere and the water molecules condense (collect together) and form clouds
condensation
precipitation
evaporation
(from bodies of water)
transpiration
(water from plants)
Clouds are NOT GAS -they are tiny liquid water particles – Think about it…YOU CAN SEE THEM so they can’t be a gas…THEY ARE A LIQUID!

6. CLOUD TYPES
THERE ARE THREE MAIN TYPES OF CLOUDS:
CUMULUS
Puffy clouds that look like cotton balls, often with a flat bottom.
These clouds signal FAIR WEATHER (blue skies and sunshine!)
CIRRUS
VERY THIN & WISPY—look like FEATHERS or HORSE TAILS.
Very high up & made of ice crystals. Usually mean FAIR WEATHER
STRATUS
These clouds COVER the sky like a BLANKET
These clouds often bring LIGHT DRIZZLY RAIN –
NOT thunderstorms.

7. YOU CAN ADD PREFIXES TO CLOUD NAMES TO DESCRIBE THEM BETTER
YOU CAN ADD PREFIXES TO CLOUD NAMES TO DESCRIBE THEM BETTER
~ ALTO- means the clouds are HIGH
IN THE ATMOSPHERE:
-Altocumulus – high cumulus clouds
-Altostratus – high stratus clouds
~ NIMBO or NIMBUS -means the clouds
contain RAIN:
-Nimbostratus – blanket-like clouds that
contain rain
-Cumulonimbus – Cumulus clouds that
grow really tall and are
often ANVIL shaped.
Cumulonimbus clouds produce SEVERE WEATHER like THUNDER, LIGHTNING, HAIL, STRONG WINDS & sometimes TORNADOES!