Unit 2 – Lesson 3 Clouds

Unit 2 – Lesson 3 : 

Unit 2 – Lesson 3 Clouds

How do clouds form? : 

How do clouds form? Did you ever wonder how a sky could be totally blue and a few hours later be covered with white puffy clouds? How about a partly cloudy sky that turns gray and stormy within an hour? Clouds are simply masses of tiny water or ice particles suspended in the atmosphere. Let’s learn more about how they form!!

Cloud Formation : 

Cloud Formation Clouds start in the atmosphere as water vapor (water that exists as a gas) Think of a tea kettle….It is the water heating and changing into a gas that makes the kettle siren The process of water changing from a liquid to a gas is called EVAPORATION

Water Vapor in the Atmosphere : 

Water Vapor in the Atmosphere As water evaporates from the Earth’s surface it rises and cools REMEMBER -- As one travels higher in the troposphere, the temperature decreases Cooler air cannot hold as much water vapor as warmer air Water vapor in the cooler air will condense to form liquid droplets The liquid droplets form a cloud

Condensation : 

Condensation Scientific term for the changing of water vapor (gas) into a liquid form In the atmosphere, water vapor must condense on a solid, suspended particle to begin forming a cloud These solid particulates in the atmosphere that form the center of a cloud are called CONDENSATION NUCLEI

Slide 6: 

Cooler temperatures inside the glass; warmer temperatures outside the glass cause water vapor to condense on the surface of the glass!

Condensation : 

Condensation Condensation in the atmosphere changes water vapor into droplets of water The droplets of water molecules collect around the condensation nuclei to form a cloud When the conditions of the atmosphere allow for the liquid droplets to increase in size, they will fall to the Earth’s surface as precipitation (rain, sleet, snow and hail)

Slide 8: 

Fog is nothing more than a cloud that touches the Earth’s surface!!

Three major cloud types : 

Three major cloud types Stratus Cumulus Cirrus

Stratus Clouds : 

Stratus Clouds Stratus means layers These are clouds that form in layers Low clouds that range from the surface to 2,000m in altitude

Cumulus Clouds : 

Cumulus Clouds Cumulus means ‘piled’ or ‘heaped’ Puffy clouds that resemble pillows in the sky Middle clouds; range from 2,000 to 6,000 m in altitude

Cirrus Clouds : 

Cirrus Clouds Highest clouds in the sky Above 6,000m in the troposphere Cirro- and cirrus means ‘curly’

Conclusion : 

Conclusion Clouds are a collection of water droplets Formed from water vapor condensing on a condensation nuclei in the atmosphere The three main types of clouds are stratus, cumulus, and cirrus The learning activities in this unit and the group project will help you learn more about clouds.