Weather and Water Cycle Unit Study Guide
What happens daily to the water on Earth?
The water on Earth remains in a continuous cycle. Water covers almost three-fourths of the Earth’s surface with nearly
97% found in the oceans.
How does water change from solid to a liquid and to a gas? Water changes due to the temperature around it.
Solid
Liquid
Gas
if it is cooled it
remains in the same state
becomes a solid
becomes a liquid, then solid
if it is heated it
becomes liquid
becomes a gas
it stays as a gas
What is the water cycle? The main stages include: evaporation, condensation, and precipitation
The water cycle involves liquid water being evaporated, water vapor condensing to form rain or snow in the clouds which
falls to the earth. Bubbles that form and rise when water is boiling consist of steam (or water vapor). The gas escaping
from boiling water is water vapor. When this vapor condenses in the air it is visible as tiny water droplets. Water left in an
open container evaporates, changing from liquid to gas.
Condensation is water vapor in the air, which cools sufficiently to become a liquid. This usually happens when the water
vapor comes in contact with a (cool) surface. Raindrops’ shape is based on their size. Small raindrops are spherical,
medium sized raindrops are a bit flattened but still basically spherical, and larger raindrops get distorted until they break
into smaller drops. The shape is dependent upon the surface tension of water and the air pressure pushing up on the drop
as it falls. Rain begins to fall when water drops in the cloud are too heavy to remain airborne. Clouds move when wind
blows them. Thunder and lightning are the visible and auditory effects of a massive charge transfer between clouds
How are clouds formed?
Clouds are formed during the condensation stage of the water cycle. Clouds are the collection of water droplets on dust
particles high in the air. As water continues to condense within the cloud, it becomes very heavy, and the water droplets
fall to Earth as precipitation.
What are forms of precipitation?
Rain- snow, sleet, and hail.
Types of clouds:
Cumulus
Stratus
they look puffy similar to cotton balls
form low in the atmosphere and
usually cover the sky
indicate fair weather, but as a it grows
rain can develop
Heavy precipitation does not usually
fall but moderate rainfall or snow fall is
possible
Cirrus
for high in the atmosphere where the
air is very cold, made mostly of ice
crystals
At what temperatures does water become a solid and at which water becomes a gas?
Water becomes a liquid at 32°F or 0°C
Water becomes a gas at 212°F or 100°C
How can we tell the difference between weather and climate?
Weather is the condition of the atmosphere at a certain place and time. Climate is the pattern of weather an area
experiences over a long period of time.
What is a warm and Cold Front?
A Cold Front is when a cold air mass moves under a warm air mass. The warm air is pushed up and cooled. This will
cause heavy rain, thunderstorms,or snow. They usually move quickly. Map symbol:
A Warm front forms where a warm air mass moves over a cold air mass. As the warm air moves over the cold air
stratus clouds form. They produce rain or snow that lasts for hours Map symbol:
The following weather instruments measure:
rain gauge-how
ThermometerAnemometermuch rain has
measures
measures wind speed
fallen//measured in
temperature
inches
Hygrometermeasures amount of
humidity in the air
Barometer
-measures air
pressure
wind vane
- shows wind direction
Key Vocabulary:
water cycle, solid, liquid, gas, evaporation, condensation, precipitation, anemometer, barometer, high pressure, low
pressure, humidity, rain gauge, thermometer, temperature, wind vane, weather, climate, clouds, cumulus, nimbus, cirrus,
stratus, rain, snow, sleet, dew, fog, meteorologist, front, weather map, weather symbols