2. Lesson 4.01 The Atmosphere. Key Points: -The air that surrounds the earth is called the atmosphere. -The layers of the atmosphere are: Troposphere, Stratosphere, Mesosphere, and Thermosphere. -Warmth, Protection (Ozone Layer-Sun’s Harmful Rays) (Meteorites also), Air, Weather. -Questions: Where do planes fly? Where is the Ozone Layer located? Where does the weather happen? Where are satellites located?

3. Lesson 4.02 What is Weather? Key Points: -Weather is the current conditions in the troposphere. In other words, “What is going on outside right now.” -Weather deals with: Temperature, Humidity, Visibility, Clouds, Wind, Sunshine, Precipitation. -Weather makes life on earth possible by giving us water to drink and to help grow our crops. Question: Which is weather? It is raining today. Or It is usually warm in Florida.

4. Lesson 4.03 Things that affect Weather! Key Points: -The two main things that affect the Weather are: Air Currents (Jet Stream) and Ocean Currents! -The Jet Stream is caused by Differences of temperature, density, and pressure between air masses. -The Jet Stream steers storms and moves around warm and cold air. -Ocean currents are caused by the wind. Question: What are the 2 main things that affect the weather?

5. Lesson 4.04 Fronts and Predicting the Weather. Key Points: -There are four different types of fronts that we are going to go over. -A cold front is when a mass cold air moves into a mass of warm air. Since the warm air is more dense than the cold air, the warm air is pushed away and over the cold air. -A warm front is when a warm air mass moves onto a cold air mass. Since the warm air is less dense than the cold air, the warm air moves over the cold air. -A stationary front is similar to a warm front, but the front does not move. -An occluded front is the combination of a cold front and a warm front. -Fronts can be used to predict the weather. Question: How many different front types are there?

6. Lesson 4.05 Humidity Key Points: -Humidity is the amount of water vapor that is in the air. -Humidity is caused by temperature and proximity to the ocean. -When the air reaches 100% humidity, this means that the air cannot hold any more water. That is when dew appears! Question: Can you name a place with high humidity?

7. Lesson 4.06 Clouds and Precipitation Key Points: -Steps to forming a Cloud: Step 1: Warm air rises. Step 2: As the air rises, it gets colder. Step 3: The air is now colder, so the evaporated water falls out of the air. Step 4: The water droplets form clouds. -3 Cloud Types Cirrus: Cirrus clouds are very thin and wispy clouds. They do not affect the weather much. Stratus: Stratus clouds are long flat clouds that spread across the sky. These clouds may bring light rain or snow. Cumulus: Cumulus clouds are cotton-like in appearance. These clouds produce heavy thunderstorms in the summer. Question: Which cloud type can appear on a rainy day?

8. Lesson 4.07 The Water Cycle Key Points: -The 5 Steps to the Water Cycle are: Evaporation: When water from lakes, streams, and the ocean turn from liquid water into water vapor. Precipitation: When water falls to the Earth from the atmosphere. This can be in the form of rain, snow, hail, or sleet. Runoff: When precipitation gathers together and flows on the surface of the ground and flows back to streams, lakes and oceans. Condensation: When water vapor in the atmosphere turns back into liquid water. Transpiration: When water in plants evaporate into the water vapor. Question: True or False: The Water Cycle helps move water around the earth?

9. Lesson 4.08 Extreme Weather Key Points: Extreme weather is any weather that is different from the normal weather that usually happens. 3 examples of extreme weather are: Hurricanes: Hurricanes are large circular storms that are formed over warm ocean water. Hurricanes have winds that have a speed of 75 mph or more Tornadoes: Tornadoes are rotating columns of violent air that make contact with the ground. The winds in a tornado can reach as high as 250 mph. Tornadoes usually form during the summer thunderstorms. Floods: Floods happen when excess water covers the land. Question: For which type of Extreme Weather do scientists use the names of people to name the different storms that occur that year?

10. Your Module 4 Review is now Complete!