Earth’s Water Cycle for Secondary Students Global Precipitation Measurement Mission Developed by the GPM Education and Public Outreach Team NASA Goddard Space Flight Center Revised Sept. 2018 Guiding Questions • The Big Picture: Why is it important to measure rain and snow around the globe? • Earth’s Water: How much of Earth’s water is freshwater? • Freshwater versus Saltwater: Which of these do we need for our survival? • The Water Cycle: How does water move through the “water cycle? • Precipitation: Where do rain and snow come from? Are these made up of freshwater or saltwater? • GPM: How will the GPM mission measure precipitation all over the world? • NASA and Earth Science: NASA is helping us learn about our home planet! 2 ENGAGE Solid? Liquid? Gas? Freshwater vs. Saltwater How much of Earth’s water is freshwater? We will make a model of Earth’s freshwater. 1.Take the plastic cup, and imagine that the cup is a model of Earth’s surface. 2.Fill up ~ 75% with water. This represents how much of Earth’s surface is covered with water. 3.Take out one eye-dropper of water, and place it in the small medicine cup. This represents how much of Earth’s water is freshwater- ~ 2.5% 4.Take one drop of this water- this represents how much freshwater is easily accessible to us! Saltwater versus Freshwater Water on Earth Credit: Earth Forum, Houston Museum of Natural Science “Show Me the Water” video Show Me the Water Link to GPM movie Earth’s Water Cycle Earth’s Water Cycle Measuring Rainfall • Most of the water we use everyday comes from precipitation. • It is important to measure how much precipitation is falling all over the world. • We can measure precipitation using rain gauges, radar, and even from space using satellites! “Getting the Big Picture” The Global Precipitation Measurement mission Last Week’s Precipitation What can we do with the data? Flooding Landslides Extreme Events Freshwater Availability Agriculture/Famine Early Warning Land surface and climate modeling The rain and snow data gathered from the TRMM and GPM missions already provide and will extend our capabilities to study a wide range of applications for scientific research and societal benefit. World Health Questions? • Do you have any questions about Earth’s water cycle and how we are learning more about it?