Day 32

Investigation 6 part 4

Clouds & Precipitation Cont.

2 Daily Warm-Up Exercises

Day 32Imagine you are climbing a mountain. What will happen to the air pressure around you as you climb?

It will decrease because there is less and less air above you.

What will happen to the temperature?It will also decrease, because temperature decreases when pressure decreases.

Cloud Formation

• Have you seen any clouds lately?

• What did they look like?

• Where are clouds?

• Are they always in the same place?

• What is a cloud?

• What is it made of?

• Where do clouds come from?

• How do you think they form?

Cloud in a Bottle?

• Using a 2-liter soda bottle, containing 25 mL of water

• Water vapor into the air?–Shaking the bottle

–Warming the water

Shake, shake, shake

• Have we formed a cloud yet?

• NOT YET

Water Vapor?

• Increase energy inside the bottle to make the water turn to vapor?

• Remember:–Temperature and pressure

–Increased temperature = increasing pressure

Cloud recipe

• Saturate the air with water vapor–Shake the bottle–Warm the bottle by holding it in your hands–Increase the pressure to increase the temperature

• Then–Release the pressure on the bottom to decrease the

temperature (to get the water vapor to condense - dew point)

Did it Work?

• NOT YET!

• There is a piece missing

• There is nothing for the water droplets to form on!!

Condensation Nucleus

• Clouds are composed of tiny droplets of condense liquid water

• Water vapor is condensing on the particles of smoke and the plastic of the bottle

• The particle on which water vapor condenses in the air to form a cloud

In Real Clouds

• What would be the condensation nuclei in the outside air?–Dust–Smog–Air pollution–Smoke–Salt–Chemicals

Precipitation

• Water that falls from the sky

• Kinds of precipitation–Rain

–Snow

–Sleet

–Hail

Raindrops and Cloud Droplets

• Measure the average diameters

• Comparison of size - page 80 in the Resource Book

Measuring Precipitation

• Most important weather factors monitored

• Measured with a rain gauge

Labels

Visualization Exercise 6.2

Resources, P. 38

Reading

• Open to page 37 of the green resource book.

• Read “Observing Clouds”

• Answer the questions at the end of the reading.