EQ: How does the water cycle affect our weather? Name:Topic: Water Cycle Date: Subject: Science What is the water cycle? The physical movement of water in all of its phases of change. Examples of phase changes of water: Two main ideas from the water cycle to remember: Fresh water forms from salt water and energy is transferred using water. How much of the Earth’s water is salt water and where is it found? 96.5% of the Earth’s water is salt water. Found in oceans, bays, saltwater lakes, and some groundwater. How much of the Earth’s water is fresh water and where is it found? 3.5% is fresh water and it is found in lakes, rivers, streams, and even ice and snow

EQ: How does the water cycle affect our weather? How is fresh water formed? By the evaporation of water from saltwater bodies. As the water evaporates, the salt is left behind in the ocean or sea. Fresh water is transported into the atmosphere at water vapor. How does water become water vapor? The sun warms up the surface of the body of water and the water particles gain energy and evaporate. What happens to water after it evaporates? The water particles and the warmed air particles spread out and form an air mass of low density (particles that are farther apart). As this mass of air rises the air cools.

EQ: How does the water cycle affect our weather? What happens to the water vapor as it continues to rise? Eventually the air reaches a temperature at which the water vapor changes its physical state to ice crystals and liquid water, which then become visible as clouds. The water stays in the clouds until it falls to Earth as precipitation. What happens to water after it falls as precipitation? Most falls into oceans b/c our oceans cover about 70% of our planet. The precipitation that falls over land is our main source of fresh water. Where does the precipitation go that falls over land? It can flow into streams and rivers, or can run beneath the surface as groundwater. Eventually most water reaches the oceans. As water moves over the land, it can pick up contaminants in the soil and here it becomes runoff.

EQ: How does the water cycle affect our weather? Can water evaporate off of plants? Runoff can sweep away pollutants along the ground and carry them into the oceans. Surface runoff can also flow through the groundwater as subsurface runoff (under the surface runoff). How can polluted surface runoff negatively affect ocean life? A process call transpiration allows water to evaporate off of the plant’s surface and through the plants “tubes” or membranes. The water is warmed by solar energy and is pulled out of the membranes of the plants and evaporates into the air.

EQ: How does the water cycle affect our weather? The water that falls into the ocean or reaches the ocean from rivers, or streams continues the water cycle as solar energy warms and evaporates surface energy. Once the water is back in the oceans, what happens? Can water evaporate from other places like land or streams? YES! Water can circulate or move through the water cycle before it reaches the ocean. Why is it important for weather forecasters to predict the time and location of the phase changes of precipitation? Because so much water is constantly cycling around us, LOTS of energy is being transferred throughout the atmosphere weather forecasters have to keep a close watch on what phase change water is going through in a particular area.Weather forecasters are looking for a “Precipitation event” which are called storms.

EQ: How does the water cycle affect our weather? How does a weather forecaster know if a “weather event” is going to be big or not? The more energy that is released, the bigger the storm. The water cycle helps scientists and weather forecasters know where the water is before a hurricane develops and how it might affect the development of the storm. Scientist Robbie Hood uses different aircrafts to explore water vapor, water, and ice within the making of a hurricane. Robbie and her team use the ER-2 aircraft and satellites to explore the making of a hurricane. Let’s explore and find out how the water in our water cycle has been here for over a billion years and hasn’t changed very much over that amount of time!