Water and Weather

The water cycle is the movement of water through the Earth system and is driven by

• energy from the sun and by gravity.

• ocean tides and by convection.

• seasonal changes and by evaporation.

• precipitation and by absorption into the ground.

The hydrosphere is unevenly distributed on Earth. How much of Earth's water is found in the ocean?

• 51%

• 73%

• 97%

• 99.9%

What force causes the downward movement of water as raindrops, snowflakes, hail, or sleet?

• air resistance

• friction

• gravity

• tension

Most water vapor in Earth's atmosphere comes from evaporation of water from

• the polar ice caps.

• rainwater on the ground.

• the surfaces of the oceans.

• wastewater from human activity.

Water also enters the atmosphere through ___________, or the evaporation of water from plant leaves.

• condensation

• dehydration

• perspiration

• transpiration

Evaporation and transpiration occur more quickly on a hot day. Why?

• Water particles have enough energy to escape the liquid surface or leaf.

• There is much more activity from humans, animals, and plants causing disturbance.

• Evaporation and transpiration can only occur on hot days.

• The atmosphere is dryer on hot days and soaks up moisture quickly to make clouds.

The amount of water vapor in the atmosphere, known as _______, affects the way the air feels

• clouds

• fog

• humidity

• precipitation

Why does a higher absolute humidity make the air feel muggy?

• Because there are more air particles in the air.

• Because there is more water vapor in the air.

• Because air circulation is reduced, making the air still.

• Because the sun's energy is reacting with the water vapor in the air.

The amount of water vapor that air can hold depends on

• its temperature.

• cloud coverage.

• the season and time of day.

• how much wind is present.

Dew forms at the __________, or the temperature at which air is saturated with water vapor.

• water point

• turning point

• dew point

• saturation point