Among the diverse meteorological elements, this area focuses on humidity, dew, fog, clouds, rain, snow, wind and atmospheric pressure. Weather influences not only our daily outdoor activities, but also transportation, economic activities and numerous other fields. In this area, students learn the impact of humidity on our daily lives and study through experiments the process of how different weather phenomena such as dew, fog, clouds, rain, snow and wind are created. Students learn through these activities that weather is closely related to our daily lives.
The grade 5 English science unit, Weather, meets the academic content standards set in the Korean curriculum, which state students should: a) Understand the processes of cloud formation, raining and snowing. b) Understand the causes of dew and fog and the differences between the two. c) Be aware of the causes of wind and the direction changes in coastal winds during the day and at night. d) Understand the concepts of high and low atmospheric pressure and recognize their influence on weather. e) Be aware that weather has an important influence on our daily lives.
The sun has the most important role in making the weather. The heat energy from the sun warms up the land, water and air above the land. Water is everywhere - the ocean, rivers, lakes, and even your body. About 97% of Earth's water is located in the ocean. The sun heats up this water and it starts to evaporate. This means the water changes from a liquid to vapor. This warm water vapor then rises into the sky. Empty coke can Heater Tongs Tablespoon Large bowl Water 1. Put a tablespoon of water into an empty coke can. Place this can on a heater. 2. When you start to see water vapor coming out from the can, wait for one minute. 3. To finish the experiment with a bang, use tongs to take the can off the heater and put it upside down in a large bowl of cold water. Draw a picture that shows the water evaporating from the can. 1. What does evaporation mean? 2. What helps to make the water in the oceans evaporate? 1
As warm water vapor rises in the air, it begins to expand and cools down. Cooler air can t hold as much water vapor as warm air and when the air pressure drops, the vapor starts to condense on tiny dust particles in the air. As more and more water drops join together, they start to form clouds. 1.5L plastic bottle Matches Warm water Clouds vary in shape and in their height above the earth. Different types of clouds bring different types of weather. 1. Fill 1/3 of the bottle with warm water and put the lid on. 2. Take the lid off and hold a lit match near the opening of the bottle. Drop the match in and quickly put the lid back on. 3. Slowly squeeze the bottle hard and then quickly release. Draw a picture to show what happened inside the bottle. 1. What does condensation mean? 2. What does the water vapor condense on? 2
Humidity is the amount of water vapor in the air. It indicates the chances of rain, dew and fog. High humidity means a lot of water is in the air. Low humidity means not much water is in the air. Humidity can be measured using a psychrometer or hygrometer. Left: A humid forest in Borneo. 2 thermometers Tape Wet gauze Elastic band Fan Table Right: Paranol has very little water vapor in the air. A hygrometer. 1. Tape two thermometers to a table with the liquid filled ends hanging over the edge of the table by about 3cm. 2. Put a wet gauze around the end of one thermometer using the elastic band. Dry 3. Blow a fan on the thermometers until the temperature doesn't drop any further. Dry - Wet Look at the temperatures on the thermometers and complete the table. Then, use the chart on the right to find the humidity in the classroom. o Dry thermometer Wet thermometer Difference between dry and wet Temperature 1. What was the humidity in the classroom? 3
The average water molecule remains in the air for about ten days. Glass jar Eventually, the water vapor cools and condenses back into liquid Hot water Petri dish water. As these water droplets grow, they become too heavy to Ice remain in the clouds. When this happens, the droplets fall from the Insta-snow powder sky as precipitation. The liquid form of precipitation is known as rain. If the air is too cold, the water vapor changes straight into ice without turning into a liquid. The cold air means that it doesn t melt on the way down. This is how snow is formed. 1. For rain: Pour about 5cm of very hot water into the glass jar and put a petri dish on top. 2. After a few minutes, put some ice cubes in the petri dish. 3. For snow: Add 1 scoop of Insta-snow powder to 60mL of water in a jar. Draw a picture to show how rain is made. 1. How is rain made? 2. How is snow made? 4
As warm air cools, the water vapor starts to condense. Dew is water that forms on objects in the form of droplets as the water vapor condenses. It can form in the morning and evening when temperatures get low. Fog also occurs when water vapor condenses as the temperatures get low, but unlike dew, it doesn t form on objects. Instead, it is water droplets that are suspended in air near the Earth s surface. Sports drink Fridge Plastic cups Ice Hot water Glass jar Strainer Ruler 1. For dew: Take a very cold drink out of the fridge and pour it into a plastic cup. Add some ice. Observe the outside of the cup. 2. For fog: Fill a glass jar with hot water for about 1 minute. Pour most of the water out, but leave about 3cm in the jar. 3. Put a strainer on top of the jar and add a few ice cubes. Observe what happens inside the jar. Draw a picture of the dew and fog you made. 1. How are dew and fog similar? 2. How are dew and fog different? 5
Winds are simply the air around us moving. Warm air rises and cooler air moves in to replace it. During the day, the sun heats the land faster than the oceans, so the warm air from the land rises and the cooler air from the oceans move towards the land. However, at night the oceans keep the heat it gained for longer than the land. This means that as the warm air above the oceans rise, cooler air from the land moves towards the ocean. This movement of air is known as convection. Rectangular box 2 plastic bottles Cling wrap Tape Scissors Candle Lighter Incense Day winds Night winds 1. Cut the bottom off the two plastic bottles. Draw a picture of the convection box showing the convection currents. 2. Make a hole on one edge of the open box. Make a hole on the opposite edge and put the necks of the bottles in there. Use tape to cover any holes between the bottles and the box. 3. Put the candle in the box on the right-hand side. Tape cling wrap on the open side so that it completely seals the open box. Hold incense above both plastic bottles and observe. 1. What is wind? 2. Why do you feel the wind blowing in from the ocean during the day? 6
Tornadoes are violent storms that form in thunderclouds. They are made when warm, moist air crashes into cold, dry air. Then, the warm air and the cold air start to spin around and a funnel starts to form. This funnel can turn into a tornado, which is wind spiraling around that hits the ground. The wind can reach speeds of 500km/h. 500mL pet bottle Teaspoon Food coloring Vinegar Dish detergent Glitter Water Tornadoes can cause a lot of damage. They can rip off roofs and blow things around. They are very dangerous. 1. Fill the bottle about two-thirds full of water and add a few drops of food coloring. 2. Add 1 teaspoon of dish detergent, 1 teaspoon of vinegar and some glitter. Screw on the lid of the bottle tightly. 3. Shake the bottle and then twist it to make the liquid spin inside. Draw a picture of your tornado. 1. What is a tornado? 2. Why are tornadoes dangerous? 7
The atmosphere pushes down on the surface of the Earth. When air is heated from below, it expands. It starts to rise and stops pressing down hard on the Earth s surface. This is known as a low pressure system. The air is warm and moist and usually brings stormy weather and strong winds. Hairdryer 2 ping pong balls 2 straws Blu-tack Air pressure systems As cooler air pushes down, it creates a high pressure system. The cool, dry air usually brings fair weather and light winds. 1. For high pressure: Put Blu-tack on both ends of the straws. Stick the straws onto a table. Stick the other end to the ping pong balls. 2. Turn on the hairdryer and aim between the two ping pong balls. 3. For low pressure: Turn on the hairdryer and blow it upwards. Try to keep the ping pong ball in the air stream. Draw pictures to show what happened to the ping pong balls in both the high and low pressure activity. 1) What creates a low pressure system? 2) What type of weather do high pressure systems usually bring? 8
Weather forecasting is a prediction of what the weather will be like in an hour, tomorrow or next week. Fairly accurate predictions can be made using computers models, observations and through understanding patterns. Markers Poster paper People use weather forecasts to help them decide what clothes they should wear. It helps people to plan their activities. A forecast of rain might mean that people will plan for something to be done indoors, while sunny weather might mean a trip to the park. 1. Watch a weather forecast on the news. Take notes of the information that is presented. 2. Use the ideas you got from the news to create your own weather forecast. Write down what information you would like to present and rehearse it. 3. Perform your weather forecast for the class. Brainstorm your ideas and information. 1) What type of information does a weather forecast give? 2) How are weather forecasts useful for people? 9