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:
A thermometer measures wind speed and direction outside the weather station every hour.
Corrected: A thermometer measures temperature; an anemometer measures wind speed at a station.
Thermometers use liquid that expands with heat to show temperature, while anemometers use spinning cups to measure wind.
2. Fix the sentence:
Rain gauges record air pressure changes that help meteorologists predict weather storms approaching.
Corrected: Rain gauges record rainfall amounts; barometers record air pressure changes for forecasts.
Rain gauges collect falling water in a measured tube, while barometers detect rising and falling atmospheric pressure for predictions.
3. Fix the sentence:
Barometers measure how much rain falls during a storm in inches accurately.
Corrected: Barometers measure air pressure; rain gauges measure how much rain falls.
Barometers track atmospheric pressure changes signaling weather shifts, while rain gauges only collect and measure precipitation depth.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. An anemometer measures wind speed using small cups that spin in the breeze.
Anemometers count rotations per minute, allowing meteorologists to calculate exactly how fast wind is blowing in any direction.
2. A rain gauge measures the amount of rain that falls during a storm.
Rain gauges collect precipitation in a calibrated cylinder, letting scientists track total rainfall over hours, days, or seasons.
3. A barometer measures air pressure to help predict whether weather will improve.
Barometers track atmospheric pressure changes that signal approaching weather systems, helping meteorologists make accurate short-term forecasts daily.
4. A thermometer measures temperature using liquid that expands when heated by air.
Thermometers rely on the principle that liquids expand with heat, allowing accurate temperature readings on a marked scale.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Why might a meteorologist use a barometer before predicting a storm?
Sample answer: A barometer shows falling air pressure, which usually signals that a storm system is moving into the area soon.
Falling barometric pressure indicates rising warm, moist air that often forms clouds and storms within several hours afterward.
2. Which two instruments would you need to record a thunderstorm completely?
Sample answer: You would need a rain gauge to measure rainfall and an anemometer to record wind speed during the storm.
Recording rainfall and wind together gives a fuller picture of storm intensity, helping scientists compare events across different times.