Download EARTH SCIENCE Chapter 3 Climate Lesson l Water exists as a

EARTH SCIENCE
Chapter 3 Climate
Lesson l
Water exists as a solid (icicles), a liquid (raindrops), and a gas
(water vapor).
Water vapor is invisible but always present in the air.
Humidity is a measure of the water vapor in the air.
Particles in a solid are packed tightly together. A solid keeps
its shape and volume.
Particles in liquids are farther apart and slide past each other. A
liquid keeps its volume but changes its shape to fit its container.
Particles in gases move freely and spread out the farthest. A gas has
no definite shape or volume.
Water freezes and ice melts at 0 C (32 F). Water boils at 100 C
(212 F).
The water cycle is the ongoing process whereby water on the earth
evaporates condenses, and forms clouds, falls as precipitation, flows or
runs off into bodies of water or becomes groundwater.
Lesson 2
Weather describes the temperature, precipitation, winds, humidity,
clouds, and other conditions in a particular place at a particular time.
Climate describes the weather conditions in a particular place at
different times and seasons over many years.
Gases that absorb infrared energy, mainly water vapor and carbon
dioxide, are called greenhouse gases. Gases in the atmosphere
absorb infrared radiation for the earth’s warmed surface.
The green house gases absorb the energy and keep the earth warm.
This process is called the greenhouse effect.
Because the earth is a sphere it is heated unevenly by the sun. Most
of the sun’s energy that reaches the Earth is absorbed by Earth’s
surface.
Because the earth is tilted, parts of its surface are tilted toward
the sun at different times of the year. The tilt affects the amount
and angle of sunlight a place gets, causing seasons.
Water cycle, Earth’s shape and tilt, ocean currents, global winds,
greenhouse gases, and natural events all effect our daily weather.
They also make or affect the climate on Earth.
Lesson 3
The temperature of a large body of water, such as a lake or ocean,
doesn't change much during the day.
Water warms and cools more slowly than land.
Land absorbs energy from the sun and warms quickly in the daytime. It
loses energy and cools quickly at night.
Places that are not near the water or are in large open areas are
more likely to have big changes in temperatures from day to night
and throughout the year.
Winds can influence how much a nearby body of water affects the
temperature of the land.
In the United States, the winds generally blow from west to east.
The temperature of the water in the currents can affect the climate
of the land they pass near.
The earth's rotation makes the path of the global winds curve.
Global winds occur because of temperature differences.
Winds carry heat energy and water vapor with them when they move
and can change the climate of the land over which they travel.
The shape of the land such as mountains can also affect the
amount of precipitation an area receives.
High elevations can cause precipitation. As warm, moist ocean air
blows onto land and meets mountains, it rises and cools. The water
vapor in it condenses, clouds form, and precipitation falls.
By the time the air reaches the other side of the mountain, it has
lost its humidity. This side of the mountain range then tends to
have a dry climate.
Lesson 4
Some natural events can change climate and weather. Volcanic
eruptions release dust and ash and sulfur dioxide into the
atmosphere.
These particles may then be carried by winds around the world,
blocking some of the sun's energy and cooling temperatures.
Another event called an El Nino. This is the movement of a huge mass
of warm water in the Pacific Ocean that occurs every two to seven
years.
A rise in the earth's temperature is called global warming. Global
warming could result from the greenhouse effect.