1. Weather Reviewing the Big Ideas

2. Q: What affects the amount of water vapor the air can hold? A: The temperature of the air! –Warm air can hold more water vapor than cool air –Air is like a sponge: there are spaces between air molecules for water to fit in –Warm air expands (spreads out), leaving more room for water molecules

3. Q: When different types of air masses collide or bump into each other, what is usually the result? A: Clouds and Precipitation! –When air masses collide and don’t mix, the warm air is forced upward. It cools off in the chillier atmosphere, and water condenses into droplets. Clouds form. If the air is humid enough, precipitation occurs.

4. Q: What happens to molecules when heat energy is added to a substance? A: They move faster and spread out! Warm air expands and rises. Cool air contracts and falls toward the earth. Like the liquid in a thermometer.

5. Q: What are the three main conditions of the atmosphere that change constantly and affect the weather? A: Temperature, Pressure and Moisture. -These change daily and from place to place. -They work together to cause changes in weather.

6. Q: What causes wind? A: Unequal heating of the atmosphere cause wind. -Some parts of the atmosphere receive more energy from the sun. -As air warms, it expands and rises (lower pressure, less dense). -Cooler air (higher pressure, more dense) rushes in to take its place. -Air moves from higher pressure to lower pressure. -This horizontal movement of air is called wind.

7. Wind

8. Q: How do meteorologists predict the weather? What daily changes do they observe and what tools do they use? A: Scientists observe the changing conditions of the atmosphere, such as: –Air pressure, using a barometer –Temperature, using a thermometer –Moisture/Humidity, using a psychrometer Wind Speed, using an anemometer Wind Direction, using a wind vane

9. Meteorologists cont. Meteorologists use tools and technology to collect and analyze weather data, such as: –Weather balloons –Satellites –Computers –Weather services (like the National Weather Service) –Weather Maps

10. Meteorologists cont. Meteorologists need certain skills to forecast the weather: –Collecting and Analyzing Data –Inferring –Predicting

11. Q: What are independent and dependent variables? A: Independent variable= the variable that you change in the experiment (the one you are testing) –Example= heat energy Dependent Variable= the variable that changes as a result of the independent variable (depends on it) –Example= temperature

12. Q: What is a constant? A: The thing(s) that stay the same in the experiment -Example- the heat lamp, the amount of material, the timer, etc.

13. Try It Out! Michelle and Lynn are designing an experiment to answer this question: Does adding fertilizer make plants grow taller? –Independent variable= –Dependent variable= –Constant(s)= –Procedure= –Data Table=