1. Take 5 minutes to work on your Landforms Gallery Walk.

2. Tilt
Earth’s Tilt: The north polar axis of the earth always points toward the North Star and is tilted at 23½ ° from perpendicular.
Because of the tilt, the length of the day changes as we rotate. Ex: Summer days are the longest.

3. As we revolve, the North Pole sometimes points toward and sometimes points away from the sun.
When the North Pole points toward the sun it has constant daylight and the South Pole has constant darkness.

4. South Pole photo – time delay 30 minutes as the sun never sets.
Solstices
Northern Hemisphere
Dec.21 is the shortest day of the year and the first day of winter.
The North Pole has a 24 hour night.
Southern Hemisphere Dec. 21 is the longest day of the year and the first day of summer.
The South Pole has a 24 hour day. The Antarctic Circle has 24 hours of sunlight.
South Pole photo – time delay 30 minutes as the sun never sets.

5. Equinox Equinox means equal night.
It occurs twice a year when the poles are not pointed toward or away from the sun and the entire earth has 12 hrs of sun.

6. June 21: in the Northern Hemisphere is the longest day of the year and the first day of summer = sun’s rays are most direct at the Tropic of Cancer.
The North Pole and the Artic Circle – north of 66.5 degrees – have 24 hours of sun.
What is happening at the South Pole?

7. March 21 – Spring Equinox in the N. Hemisphere and Fall in the S
March 21 – Spring Equinox in the N. Hemisphere and Fall in the S. Hemisphere.
Sept. 22 – Fall Equinox in the N. Hemisphere and Spring in the S. Hemisphere.
Days between solstices and equinoxes get gradually shorter or longer and this creates seasons. The mid-latitudes are most effected by Earth’s revolution and have four distinct seasons.

8. Climate
Weather: the condition of the atmosphere at a given place and time.
Climate: average weather – weather conditions averaged over a long period of time; includes rare events (hurricanes) and long term global changes

9. Air Pressure Air Pressure the force exerted by air.
causes winds and ocean currents.
Unequal heating of the earth causes pressure differences = wind.
Wind always flows from high to low pressure areas.

10. Wind Belts
The planet’s prevailing winds usually blow from the same direction.
Equator – Doldrums
Tropics – Trade Winds
Mid-Latitudes – Westerlies
Poles – Polar Winds
POLAR WINDS
WESTERLIES
TRADE
WINDS
DOLDRUMS

11. Ocean currents Comparable to rivers but in the ocean.
They move warm and cold waters around the earth.
Warm waters flow away from the equator towards the poles.
Cold waters flow back toward the equator.

12. Ocean currents

13. The Tropics
The Tropics: areas near the equator that receive the most constant sun.
The Tropics are warm, low-latitude areas from 0 to 30 degrees.
The direct rays hitting the equator are stronger because they are concentrated on a small area.
Great Barrier Reef

14. The Tropics Prime Meridian Equator
Zero degrees E or W
Tropic of Cancer: Northern Hemisphere at 23.5 degrees N.
Equator
Zero degrees N or S
Tropic of Capricorn: Southern Hemisphere at 23.5 degrees S.
The degree is determined by the tilt of the axis.

15. The Polar Regions
The Poles: high latitude areas, very cold and marked by the North and South Poles at 90 degrees latitude.
The higher the latitude, the lower the temperature.
The lower the latitude, the higher the temperature.

16. The Middle Latitudes
The mid-latitudes: temperatures vary between hot and cold depending on the amount of solar energy (or time of year).
The mid-latitudes have four distinct seasons.