Science Jolt Dec 1. 2017 In your journal, describe a time when you experienced or observed condensation.

Water in the Atmosphere

The Water Cycle The movement of water between the atmosphere and the Earth

Evaporation The process by which water molecules in liquid water escape into the air as water vapor.

Humidity A measure of the amount of water vapor in the air.

Relative Humidity Measured with a psychrometer The % of water vapor in the air compared to the maximum amount that the air can hold Warm air holds more water vapor than cold air

psychrometer

Condensation The process by which molecules of water vapor in the air become liquid water.

Dew Point The temperature at which condensation begins is the dew point (RH = 100%) When the dew point is below freezing, frost will form

Create a cloud….

Cloud Formation Clouds form when warm humid air rises and cools to the dew point (rising air = ___Pressure) The water vapor condenses on tiny particles (“cloud dust” - condensation nuclei) – Particles!

Types of Clouds Three main Types… Cumulus: puffy (cotton) Stratus: blanket like (layer) Cirrus: feathery/wispy (high)

Types of Clouds Nimbus: producing rain Alto: high in the atmosphere

Fog Clouds that form on the ground Forms when there are cool temperatures after a warm humid day

What instrument is used to measure relative humidity? What conditions are needed for clouds to form? Describe each of the three main types of clouds.

SCIENCE BLOCK C and E combined Questions: Name the clouds…show 4 clouds and match Read relative humidity given a wet and dry bulb reading and using the chart Describe how clouds form Where do cirrus clouds form? What is the instrument used to measure relative humidity? Name the three main cloud types and their shapes Identify air masses from a diagram showing their location What is relative humidity and how is it measured? When dew point is ___________ frost is formed Describe how clouds and fog forms Describe the four air masses What do clouds need to form (warm rising air/condensation nuclei) How do you determine the last name of an airmass? How does pressure affect clouds? (if you increased pressure what would happen in a “cloud in a bottle” demo?