LATITUDE AND CLIMATELOCATION, LOCATION, LOCATION
OBJECTIVE:
Identify and locate the four special lines of latitude and explain how climate is affected by location.
BELL RINGER
Luis goes to the hardware store to make a purchase. He asked the clerk, “How much will six cost?” The clerk thought for a moment and said, “Three dollars.” Luis then asked, “How much will thirty six cost?” “Six dollars,” replied the clerk. Luis scratched his head and said, “If I bought three hundred sixty, how much would that cost?” “That will cost you nine dollars,” said the clerk. What was Luis buying?
YESTERDAY’S ANSWER
Sid would be 160 cm tall (that’s about 5’3”) If Sid’s height is 80 cm plus half of his height, then 80 cm must be the other half of his height 80 + 80 = 160
CLASSROOM RULES
Comply with all federal, state and district policies
Do not do anything that creates unsafe or unhealthy conditions in my classroom
Do not do anything that interferes with your learning
Do not do anything that interferes with anyone else’s learning
Do not let anyone else interfere with your learning
CLASSROOM PROCEDURES
Bring and use the proper materials at the proper time No gum or food Do not talk except when the activity permits or when
you have a question (raise your hand first). Stay in your seat unless you have permission Do not do work from other classes unless you have
permission Listen carefully to instructions, execute them to the best
of your ability, and ask if you do not understand them Participate in the lesson by doing the correct activity at
the correct time: listen, ask questions, discuss, read, write, research.
VOCABULARYTerms we will be using today
Arctic Circle
Tropic of Cancer
Tropic of Capricorn
Antarctic Circle
Precipitation
Growing Season
THE MAGIC NUMBER
The four special lines of latitude all involve one number: 23.5° The Arctic Circle is 23.5° from the North Pole
The Tropic of Cancer and Tropic of Capricorn are each 23.5° from the Equator
The Antarctic Circle is 23.5° from the South Pole
WHY 23.5°?
AXIAL TILT IS THE REASON FOR THE SEASONS
Because the Earth’s axis is tilted 23.5°, the angle of the sun’s rays is different at different points on the surface, depending upon where Earth is in its orbit
When the sun shines more directly on the surface, more heat is applied to the surface
When the sun shines less directly (the proper term is “obliquely”), less heat is applied to the surface In the Northern Hemisphere, the sun shines more directly
during April-September and more obliquely during October-March
It’s opposite in the Southern Hemisphere
YOU DO
On your world map Fill in your name, period and the date
Use a ruler, a folded piece of paper or something else with a straight edge to draw the Equator and the two Tropic lines on the next slide
Help your partner if they need it
LOCATIONS OF THE TROPICS
Tropic of Cancer
Tropic of Capricorn
AXIAL TILT IS ALSO A REASON FOR CLIMATE
Between the Tropic of Cancer and the Tropic of Capricorn, the sun always shines most directly
There will be two days during the year when the sun passes directly overhead (on the Tropics, it happens once per year and that day is called a “solstice”) “The Tropics” are sometimes called the “low Latitudes”
Temperatures are generally high with no clear differences between seasons (depending on elevation)
Usually lots of rain and very long growing season
Day/Night are fairly equal, year round and twilight is short
YOU DO
On your world map: Use a ruler, a folded sheet of paper or something
with a straight edge to draw the two Circles on the next slide
Help your partner if they need it
LOCATION OF THE CIRCLES
Arctic Circle
Antarctic Circle
AXIAL TILT IS ALSO A REASON FOR CLIMATE
Between the Poles and the Circles, the sun always shines most obliquely
There will be one or more days during the year when the sun never rises and one or more days when it never sets The area is called “Polar” or the “high Latitudes”
Temperatures are generally cold with very long winters and very short growing seasons
Day/Night times are most unequal
Long periods of twilight
LOCATION OF THE TEMPERATE ZONES
Northern Temperate Zone
Southern Temperate Zone
AXIAL TILT IS ALSO A REASON FOR CLIMATE
Between the Tropics and the Circles are the temperate zones or mid-latitudes Fairly distinct seasonal temperature differences
Moderate precipitation (either as rain or as snow/ice)
Seasonal differences in the number of hours of day/night
Long or moderate growing seasons
Moderate to long periods of twilight (longer twilight as you move north)
LATITUDE DETERMINES PRECIPITATION?
POPULATION PREDICTIONS
If Latitude affects temperatures (it does) AND
If Latitude affects precipitation (it does) THEN
Where would be expect to find people living? Many people living in areas where there are moderate
temperatures and enough rainfall to support agriculture
Many people living in areas where there are high temperatures and enough rainfall to support agriculture
Few people in areas with moderate temperatures and little precipitation
Few people in areas with low temperatures and lots of precipitation
EFFECT ON PEOPLE
CONCLUSIONS
Latitude has a very strong effect on temperatures, but it is not the only factor Temperatures are a major factor in the length of the
growing season (edible plants do not handle freezing well)
Latitude has a very strong effect on precipitation, but it is not the only factor Temperature and rainfall determine what kinds of plants
can be grown (snow doesn’t help until it melts)
The eastern half of North America has both moderate temperatures and good precipitation, so we expect to find many people and there are
HOMEWORK
Given a blank world map:
Draw and label:
Prime Meridian
Equator
Tropic of Cancer
Tropic of Capricorn
Arctic Circle
Use a ruler or straight-edge to make the lines (no freehand)
Label:
Atlantic Ocean
Pacific Ocean
Indian Ocean
Arctic Ocean
North America
South America
Europe
Asia
Africa
TOMORROW
We will use Latitude and Longitude as a coordinate system to locate places on the Earth’s surface.
