Earth's Systems: Water and Weather — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
All clouds bring rain immediately when they appear in the sky above us.
Corrected: Cirrus clouds rarely bring rain; only cumulonimbus clouds usually produce heavy rain.
Cirrus clouds are made of ice crystals high up and rarely produce precipitation, while cumulonimbus clouds tower tall and dump rain.
2. Fix the sentence:
Tornadoes form over warm ocean water and grow into very large hurricanes quickly.
Corrected: Hurricanes form over warm ocean water; tornadoes form on land from severe thunderstorms.
Hurricanes need warm seawater above 80 degrees, while tornadoes spin down from thunderstorm clouds over land.
3. Fix the sentence:
Stratus clouds are tall puffy clouds that look like cotton balls floating high.
Corrected: Stratus clouds are flat, low gray layers; cumulus clouds look like puffy cotton balls.
Stratus means layered and forms low flat sheets, while cumulus clouds look like puffy heaps in fair weather skies.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. Tall, towering cumulonimbus clouds often produce thunderstorms with heavy rain and lightning.
Cumulonimbus clouds rise through the atmosphere, carrying moisture that condenses into thunder, lightning, and heavy rainfall.
2. A spinning column of air that touches the ground is called a tornado.
Tornadoes form when warm and cold air collide inside thunderstorms, creating violently rotating funnels that touch ground.
3. Thin, wispy cirrus clouds form very high in the sky and contain ice crystals.
Cirrus clouds form above 20,000 feet where temperatures are freezing, so they are made entirely of ice crystals.
4. A heavy snowstorm with strong winds and low visibility is called a blizzard.
Blizzards combine heavy snow, winds over 35 mph, and visibility under one-quarter mile for at least three hours.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Which cloud type is most likely to produce a thunderstorm, and why?
Sample answer: Cumulonimbus clouds produce thunderstorms because they grow tall, hold huge amounts of moisture, and create strong updrafts.
Cumulonimbus clouds rise high enough for ice and water to collide, generating lightning, thunder, and heavy precipitation patterns.
2. Name two differences between a hurricane and a tornado that you can observe.
Sample answer: Hurricanes form over oceans and span hundreds of miles, while tornadoes form over land and are much smaller.
Hurricanes are large, slow ocean storms lasting days, while tornadoes are small, fast land funnels lasting minutes only.