Download Water Cycle Information

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Water Cycle Information
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EVAPORATION
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PRECIPITATION
The water cycle is much more
complex than this diagram
shows. Use the information below
to help you draw and label a more
complex and realistic water cycle
diagram. Use as many of the
processes as you can. Also include
those you think others might not
choose.
RUNOFF
r Reservoir: In the water cycle, reservoirs are places where a large amount of water is stored. Clouds,
rivers, lakes, water vapor, snow, ice, and groundwater are all considered reservoirs. The ocean is the
biggest water reservoir on Earth. The amount of time water stays in any reservoir ranges between a
few seconds (in the atmosphere) to at least 740,000 years (ice in Antarctica).
r Sunlight: Heat energy from the Sun makes the water cycle happen. It warms up air and makes
water molecules at the surface of liquid water evaporate to become water vapor. Warm air and
water vapor rise up in the atmosphere.
Ocean Sciences Sequence © 2014 The Regents of the University of California
r Water vapor: When water molecules at the surface of liquid water evaporate into a gas, it is
called water vapor. Water vapor is invisible. Humidity is a measurement of how much water
vapor is in the air.
r Evaporation: The process of molecules at the surface of a liquid changing phase into a gas is
called evaporation. This happens when molecules at the surface have enough heat energy to enter
the air as a gas. An example is when liquid water molecules turn into water vapor molecules in the
air. Evaporation happens when liquid water temperatures are quite high or near fast-moving
surface air. When water evaporates, it takes heat energy from its surroundings, making the
surroundings cooler. Evaporation is the opposite of condensation.
r Condensation: The process of a gas changing phase (or turning into) a liquid is called
condensation. This happens when molecules in a gas lose energy, slow down, and move less far
apart from other molecules. An example of condensation is when water vapor turns into liquid
water. Water molecules condense out of water vapor into liquid water when the atmosphere cools
and there is a particle for the water vapor to attach to. When water condenses, it releases heat
energy into its surroundings, making the surroundings warmer. Condensation is the opposite of
evaporation.
r Precipitation: Precipitation is solid or liquid water that falls to Earth. Precipitation happens when
enough water vapor changes phase to form water droplets or ice crystals in the air. When water
drops or snowflakes become too heavy to stay in a cloud, they fall to the ground as precipitation.
Rain, snow, freezing rain, sleet and hail are all types of precipitation.
r Snow: Snow is a kind of precipitation that is made of solid water crystals.
r Rain: Rain is a kind of precipitation that forms in clouds and falls to Earth as drops of water.
Student Sheet—Ocean Sciences Sequence 1.10
r Runoff: Water that flows downhill over the ground, such as in rivers and streams, is called
runoff.
r Clouds: Clouds are visible masses of liquid water droplets or frozen water crystals. Some clouds
are made up entirely of liquid water droplets. Higher clouds where the atmosphere is colder are
made entirely of ice crystals. Some clouds are made of both.
r Cloud formation: Clouds often form when warm, humid (containing lots of water vapor)
air rises. As the warm air rises, it cools. When the warm air cools, some of the water vapor
condenses. That means the water vapor changes phase into liquid water droplets. If the air is
very cold, water vapor might change phase into ice crystals.
r Fog: Clouds that stay near the ground are called fog. When warm, humid air cools, the water
vapor in the air condenses to form liquid water droplets. Warm air often has a lot of water vapor
in it. Fog forms when warm, humid air gets cooled off near the ground. Heat and wind make fog
evaporate.
r Groundwater: Liquid water that is underground is called groundwater. Groundwater moves
slowly underground between particles of dirt, sand, and chunks of rock. About 20 percent of
Earth’s freshwater is groundwater.
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Water Cycle Information (continued)
r Transpiration: Transpiration is when plants lose water to the air in the form of water vapor.
r Frost: Frost is water vapor that changes phase into ice crystals on solid surfaces, such as plants
and windows. Frost forms when the air temperature becomes very cold. When frost forms, it
skips the liquid phase. The water vapor turns directly into solid ice when it releases heat energy
without first becoming liquid.
r Freezing rain: Freezing rain is supercooled liquid water. It is water that is at a temperature below
freezing, but it is still a liquid. Freezing rain falls as supercooled liquid water, but it freezes as
soon as it hits the ground.
r Hail: Hail forms when wind blows raindrops to the top of a storm cloud where the air is colder
than freezing. Strong winds blowing upward keep these frozen raindrops hovering high in the
storm cloud. New raindrops blow upward and hit the frozen raindrops and freeze. This covers
the frozen raindrops with new layers of ice. Once hailstones are too heavy for the wind to hold
them up, they fall to the ground.
r Sleet: Sleet is a type of precipitation. Sleet can start as rain or snow. When rain falls through cold
air on its way to the ground and freezes, it is called sleet. Sometimes, a snowflake melts when it
passes through a warm layer of air, then freezes again when it passes through a cold layer. This is
also called sleet.
r Sublimation: Sublimation is when solid water (ice) changes into water vapor, without first
changing to liquid water. Ice and snow sometimes slowly sublimate into water vapor at
temperatures that are too cold to allow melting into a liquid to occur.
Student Sheet—Ocean Sciences Sequence 1.10
Ocean Sciences Sequence © 2014 The Regents of the University of California
r Dew: Dew is liquid water that forms on the ground or on objects such as grass, leaves, cars and
spiderwebs. Dew starts as water vapor in the air. After the Sun sets, the ground gets colder and
so do objects near the ground. Because of this cooling, some water vapor in the air condenses
into liquid water on the cooler objects.