Water Cycle and Weather

Georgia Performance Standards

S4E3 Students will differentiate between the states of water and how they relate to the water cycle and weather.

a. demonstrate how water changes states from solid (ice) to liquid (water) to gas (water vapor/steam) and changes from gas to liquid to solid.

b. identify the temperatures at which water becomes a solid and at which water becomes a gas.

c. investigate how clouds are formed. d. explain the water cycle (evaporation, condensation,

and precipitation). e. investigate different forms of precipitation and sky

conditions. (rain, snow, sleet, hail, clouds, and fog)

Essential Questions• What form does water take on our earth?

• How does water change from a solid to a liquid to a gas?

• How does water change from a gas to a liquid to a solid?

• How are clouds formed?

• What is the water cycle?

• What are forms of precipitation?

• Do we drink the same water that was on earth a million years ago?

• Earth’s water exists in three states: liquid water, solid ice, and a gas that we call water vapor.

Water Cycle

• Water changes states in a process known as the water cycle.

• Liquid water gathers in oceans, seas, and rivers, and it falls as rain.

• Ice is water in its solid state. Ice forms when heat is removed from the liquid water. When temperatures fall below 32◦ F (0◦C), liquid water will freeze and becomes ice.

• Water can also take the form of a gas. Water in the gas state is called water vapor. Water vapor is part of the air, but you cannot see it. It forms when HEAT is added to the liquid water.

• When liquid water’s temperature is raised to 212◦F (100◦C), you can observe water vapor.

• Liquid water can also become water vapor (gas) at lower temperatures. This happens in a process called EVAPORATION.

• Evaporation is when the surface of the water slowly changes into a gas. The Sun causes evaporation of water.

• When the water vapor (gas) evaporates and meets cold air as it rises into the air, it forms tiny water droplets. The droplets formed by CONDENSATION.

• This is how clouds are formed

The water cycle

• The water on Earth changes from one form to another over and over again as it goes through the water cycle.

• The WATER CYCLE is the movement of water into the air as water vapor and back to the Earth’s surface as precipitation.

• Precipitation is any form of water that falls from the clouds to the Earth’s surface.

• The water in our oceans, lakes, and rivers evaporates and becomes water vapor.

• As the water vapor rises in the air, it cools and condenses into water droplets.

• These droplets form clouds. The drops become heavier as more water vapor condenses. When they are too heavy, they fall to the Earth as precipitation.

• The water cycle cleans the Earth’s water supply.

Types of clouds

• Clouds form when water vapor in the air condenses.

• A cloud that forms close to the ground is called FOG.

STRATUS clouds

• Stratus clouds are low-level clouds that form in layers. This type of cloud usually brings steady rain.

CUMULUS clouds

• Cumulus clouds are fluffy and have flat bases (bottoms). They form low in the sky and usually mean fair weather.

CIRRUS clouds

• Cirrus clouds are thin, feathery clouds made of ice crystals. They form high in the sky and also indicate fair weather.

CUMULONIMBUS clouds

• Cumulonimbus clouds bring thunderstorms.

PRECIPITATION

Precipitation is any form of water that falls from clouds to the Earth.

Rain, snow, sleet, and hail are the most common forms of precipitation.

Rain

• Rain is the MOST common form of precipitation.

Sleet

• Sleet is rain that freezes as it falls. If the temperature near the Earth’s surface is below freezing, rain will turn to ice before it hits the ground.

Snow

• Snow falls when the temperature in a cloud is below freezing. Water vapor in the cloud forms ice crystals known as snowflakes.

Hail• Hail forms when the drops of rain freeze

and strong winds carry them higher into the cloud. As hailstorms fall again, more ice forms on them and they become larger. When they are too heavy, they will fall to the Earth.

Essential Questions• What form does water take on our earth?

• How does water change from a solid to a liquid to a gas?

• How does water change from a gas to a liquid to a solid?

• How are clouds formed?

• What is the water cycle?

• What are forms of precipitation?

• Do we drink the same water that was on earth a million years ago?