| Seasonal Cycles
The earth's atmosphere is about 430 miles thick. Without this layer of
gases to protect us, we could not live. We would be scorched by the sun
during the day and frozen at night. Most of the atmosphere is a thin mix
of gases that is calm and unchanging. But the lowest 7 miles--the layer
in which we live and breathe--contains all the weather we experience,
and is thick with gases, water, and dust. As the sun warms the land and
sea beneath it, the heat keeps this lower 7 miles swirling and churning.
It is the constant swirling of this lowest layer, called the troposphere,
that gives us everything we call weather--from the gentle showers to raging
hurricanes and tornadoes.
The earth has a clear pattern of wind circulation that results from the
effect of the earth's rotation and the way that the heat of the sun is
distributed. It has become easier to view these cycles and patterns because
of photos that can now be taken from satellites orbiting the earth. These
global patterns cause weather to occur in cycles--the typhoons that are
generated from the China Sea and affect southeast Asia--the hurricanes
that begin in the Caribbean and affect the southeastern United States
and Central America--the tornadoes that travel through the American midwest.
Sample some of the following activities to learn more about seasonal
cycles of the earth.
Places To Go | People
To See | Things To Do | Teacher
Resources | Bibliography
Places To Go
The following are places to go (some real and some virtual) to find out
about seasonal cycles of the earth.
Nova Online
: Flood!
Visit a floodplain. The seasonal cycle of rivers flooding is a normal
part of nature and is part of the way that fertile soil builds itself
up. In fact, the ancient Egyptians used to refer to the annual flooding
of the Nile as the "gift of the Nile" and they welcomed the benefits that
it brought. In modern times, problems arise when humans build cities and
homes in floodplains and try to rechannel rivers to avoid flooding.
Globe Program
Visit schools around the United States as they participate in the Globe
program. Globe is a worldwide network of students, teachers, and scientists
working together to study and understand the global environment. Students
and teachers from over 7,000 schools in more than 80 countries are working
with research scientists to learn more about our planet and its cycles.
Globe students make environmental observations at or near their schools
and report their data through the internet.
National Weather Service
The National Weather Service is THE place to go to find out about weather
and its cycles.
 World
Temperature Extremes
Travel to the hottest and coldest places on the planet. What is the coldest
temperature ever recorded in Antarctica? What is the coldest temperature
ever recorded in northern North America--in the Arctic? Antarctica gets
a lot colder than the Arctic regions. This is because Antarctica is much
bigger and so the moderating effects of the oceans don't warm up the center
of the continent as much as they warm up the Arctic. Scroll down the page
to see the high and low temperature extremes for Utah. They both occurred
in the same year. What year was it? The place for the high temperature
is well-known. You may not recognize the place where the lowest temperature
ever recorded in Utah occurred. Use the Utah
Collections Multimedia Encyclopedia and find out what county this
place is in. The earth's temperature is hotter at the equator and colder
at the poles because of the difference in the angle of the sun's rays.The
temperature of an area depends on the strength of the sun's rays, which
is determined by the angle at which the rays hit the earth. Since the
earth is round, the sun's rays hit different areas at different angles--the
higher the latitude the more slanted are the sun's rays. This is why it
is colder the further north or south you get from the equator.
USA
Today Weather Highs
Check out other states' highest
recorded temperatures.. This chart shows each state's lowest
recorded temperature. Utah's lowest temperature was -69 Only Alaska
and Montana have lower record temperatures than Utah. (Montana's was -70,
and Alaska's was -80). Find out which U.S. cities have the most days per
year of temperatures
over 90 degrees. (None of the cities are in Utah). Find out which
U.S. cities have the most days per year of temperatures
below 32 degrees. (None of the cities are in Utah. Barrow, Alaska
dips below 32 degrees an average of 321 days each year!) Here's a handy temperature
calculator if you need to convert between Fahrenheit and Celsius.
Grand Canyon
Flood
Visit the Grand Canyon. In the past, the natural flooding of the Colorado
River was part of the shaping of the Grand Canyon. Today, these natural
flood cycles have been eliminated by the building of dams and the control
of the river's natural flow. Over the years, the sand bars along the river
in the bottom of the Grand Canyon have been gradually disappearing because
there are no seasonal floods to deposit sand. These sand bars provide
important habitat for wildlife. Find out why scientists created an artificial
flood in order to help restore some of the natural balances to the Grand
Canyon.
Wenatchee
National Forest
Via this webcam, visit
the Wenatchee National Forest in Washington and track the seasons. Watch
the leaves as they change from green to gold to orange to red. It has an
icicle cam to track winter changes.
Biomes
of the World
Explore a temperate deciduous
forest. This particular biome exhibits all 4 of earth’s seasons.
Find out how the animals of this biome adapt to its seasonal changes.
People To See
 Al's
Weather
Chat with Al Roker. He knows all about weather cycles and can tell you
your local weather forecast.
Hurricane Hunters
Visit with some real hurricane hunters. These Air Force men and women
fly airplanes right into the eye of hurricanes to gather data. You can
email your questions to info@hurricanehunters.com or visit their website.
Things To Do
The Old Farmer's Almanac
Virtually thumb through the old Farmer's Almanac. It has been around since
1792! It's America's oldest continuously published periodical, and it
comes out every year in September. It's also available online. It has
everything you ever wanted to know about planting cycles, weather cycles,
and more.
 Climate
Prediction Center
Check out global climate highlights and anomalies. Sometimes weather cycles
go awry.
Extreme Weather Sourcebook
Find out about the economic losses that arise from floods, hurricanes,
and tornadoes. Select "Flood" and then look at Utah's data. During which
year in Utah was the greatest flood damage sustained? Look at the hurricane
data. Which state is ranked as #1 as far as having the most economic losses
due to hurricanes? Which state is ranked as #1 for having the most economic
losses from tornadoes? In the flood data, Utah is ranked as #12 for economic
losses from floods.
Space
Weather Today
Check out the current weather on the sun.
Greenhouse
Effect
The greenhouse
effect is an increase in the temperature of a planet as heat energy
from sunlight is trapped by the gaseous atmosphere. Check out this chart
of the greenhouse effect and this one.
 A
Paleo Perspective on Global Warming
Study climate of the past. It can help us understand earth's climate of
today as well as that of the future.
Currents
Weather all over the world is affected by ocean currents. Find out more.
El
Niño - Hot Air Over Hot Water
Learn about the cycle of El Niño. El Niño is a weather condition
where a warm ocean current that is normally situated off Australia's coast
moves east toward the coasts of Equador and Peru. It also includes a weakening
of the equatorial trade winds. Its name comes from the Spanish word for
"the child" because it develops around Christmastime. Try these simple
experiments that replicate the effects of El Niño. La
Niña is kind of like the opposite of El
Niño. Its cycle involves strong trade winds and cooler Pacific
waters. El Niño and La Niña occur on average every 3 to
5 years. From NOAA,
check out these FAQs about El Niño and La Niña.
 USA
Today Weather - Tornadoes
Find out what the weather cycles are that produce tornadoes more often
at certain times of the year.
All About Glaciers
Find out about the forces that make glaciers.
The Seasons
Learn more about the seasons of the earth. This information is part of
the excellent Weather
Dude site. From the same source, find out why the sun is the source of all the weather on the earth--its even responsible for
the wind!
Scholastic
Create
a seasonal postcard.
Science
U : Seasons Reasons
Find out
what would happen to our seasons if the tilt of the earth's axis was 0°.
(Hint: You would never need your woolen mittens or Bermuda shorts).
Seasons
of the Year
Find out if seasons exist
at the equator.
Enchanted
Learning : The Seasons and Axis Tilt
Find
out the difference between a solstice and an equinox.
Mr.
Dowling’s Season’s
Page
The tilt of the earth is 23 ½ degrees.
Discover what this has to do with the seasonal cycles of the earth.
Teacher Resources
Hotlists from UEN provide internet sites to
visit to find out more about specific topics--in this case, seasonal cycles!
(You can learn how to use this WWW
Activities tool created by UEN for Utah educators).
Online activities are a listing of internet
sites with fun, interesting, and educational tasks attached to each one.
(You can learn how to use this WWW
Activities tool created by UEN for Utah educators).
Lesson Plan/Webquests
Activities
Bibliography
- Frandon, John. How the Earth Works. Reader's Digest : Pleasantville,
New York, 1992.
- Farndon, John. Weather. New York : DK Pub., 1998.
- Kahl, Jonathan D.Weather Watch : Forecasting the Weather : Minneapolis
: Lerner Publications, c1996.
- Kerrod, Robin. Weather. New York : Lorenz Books, 1997.
- Llamas Ruiz, Andres. Seasons. New York : Sterling Pub., 1996.
- Llewellyn, Claire. Wild Wet and Windy. Cambridge, Mass. : Candlewick
Press, 1997.
- Malam, John. Wacky Weather. New York : Simon & Schuster Books
for Young Readers, 1998.
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