Transcript Slide 1
Work Hard. Get Smart. IC/CER Scientist’s Name: _________________________________ Class: 8__ Date: ______________ Mrs. Bouchard– 8th Grade Science Storms Open Response Directions: We will read this aloud together and pause after each paragraph to talk about the most important points from that passage. Thunderstorms are extremely common. Across the globe, there are about 14 million per year; that's 40,000 per day! Most come and go quickly, dropping a lot of rain on a small area, but some are severe and highly damaging. Thunderstorms are most common when ground temperatures are high. This tends to be in the late afternoon or early evening in spring and summer. As temperatures increase, warm, moist air rises. At the top of the stratosphere, upper level winds blow the cloud top sideways to make the anvil shape that characterizes a cloud as a thunderhead. Clouds form when water vapor condenses. Remember that when water changes state from a gas to a liquid, it releases heat. Heat makes the air in the cloud warmer than the air outside the cloud and supplies the cloud with a lot of energy. Water droplets and ice travel through the cloud in updrafts. When these droplets get heavy enough, they fall. This starts a downdraft, and soon there is a convection cell within the cloud. Droplets traveling through the convection cell grow. Eventually, they become large enough to fall to the ground. At this time, the thunderstorm is mature, it produces gusty winds, lightning, heavy precipitation and hail. Once downdrafts have begun, the thunderstorm can no longer continue growing. The downdrafts cool the air at the base of the cloud, so the air is no longer warm enough to rise. As a result, convection shuts down. Without convection, water vapor does not condense, no latent heat is released, and the thunderhead runs out of energy. A thunderstorm usually ends only 15 to 30 minutes after it began, but other thunderstorms may start in the same area. Severe thunderstorms grow larger because the downdrafts are so intense, they flow to the ground. This sends warm air from the ground upward into the storm. The warm air feeds the convection cells in the cloud and gives them more energy. Rain and hail grow huge before gravity pulls them to Earth. Hail that is 1.9 cm (0.75 inch) in diameter is not uncommon. Severe thunderstorms can last for hours and can cause a lot of damage due to high winds, flooding, intense hail, and tornadoes. Lightning is a huge release of electricity that forms in cumulonimbus clouds. As water droplets in the cloud freeze, positive ions line the colder outside of the drop. Negative ions collect in the warmer inside. If the outside of the drop freezes, the water inside often shatters the outside ice shell. The small, positively-charged ice fragment rises in the updraft. The heavier, negatively-charged water droplet falls in the downdraft. Soon the base of the cloud is mostly negatively-charged and the top is mostly positively-charged. The negative ions at the base of the cloud drive away negative ions on the ground beneath it, so the ground builds up a positive charge. Eventually the opposite charges will attempt to equalize, creating ground to cloud lightning. Only about 20% of lightning bolts strike the ground. Lightning can also discharge into another part of the same cloud or another cloud. Work Hard. Get Smart. Scientist’s Name: _________________________________ Class: 8__ Date: ______________ Mrs. Bouchard– 8th Grade Science Storms Open Response The diagram below shows a storm forming in a large cloud. a. How do these storms form? Be sure to include information about your knowledge of updrafts and downdrafts. (USE THE BACK AS PRACTICE SPACE) _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ CER Work Hard. Get Smart. CLAIM (YOUR ANSWER TO THE QUESTION): _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ EVIDENCE (tell me what you know about the topic, do not explain how it answers the question. This section is just for facts and knowledge): _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ REASONING (Now, relate your evidence to your claim. How does your evidence support your claim? Use transition words to start) _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ Work Hard. Get Smart. i Swap your summary with your table partner. Evaluate each other’s work. Give each other a score based on the following rubric: Score Description 4 The response demonstrates a thorough understanding of storm formation. It included a description of updrafts, downdrafts, and air temperature. It related how the temperature of air is important to create movement of air. It included a claim, evidence, and reasoning and the reasoning started with transition words. 3 The response demonstrates a general understanding of storm formation. It was lacking specific details and no transition words. 2 The response demonstrates a limited understanding of storm formation. Either the evidence or the reasoning was missing. Ideas were not explained. 1 The response demonstrates a minimal understanding of storm formation. It did not include evidence or reasoning. Many of the ideas were incorrect. 0 The response is incorrect or contains some correct work that is irrelevant to the skill or concept being measured. Key concepts were missing. Ideas that were explained were incorrect. 1st Review Score: _________ Notes from the reviewer: 2nd Review Score: _________ Notes from the reviewer: