APPARENT PATH OF THE SUN
How does the Sun’s path affect the amount of energy received on Earth?
HOMEWORK
• Textbook: read pages 257 – 260. • Do questions 17, 23-31.
SUN
• RISES IN THE EAST . . . SETS IN THE WEST
ANGLE OF INSOLATION
• Insolation: Incoming Solar Radiation is the sun's energy that enters the earth's atmosphere and surface.
• Angle of Insolation: the angle at which the sun’s rays strike the earth's surface.
• Intensity: a measure of the amount of radiation that strikes a unit area of the earth's surface.
FACTORS THAT INFLUENCE THE AMOUNT OF ENERGY RECEIVED BY THE SUN
• Angle of Insolation – lower in the mornings and evenings– Higher in the afternoons
• Duration of Insolation– In NY, Sun is out for 15 hours in Summer– In winter, Sun is out only 9 hours
• Latitude of maximum insolation– North and South Poles are much colder than the
Equator.
FACTORS THAT INFLUENCE THE AMOUNT OF ENERGY RECEIVED BY THE SUN
• Intensity of Insolation – Higher the angle of insolation, the greater or
stronger the amount of energy– Lower the angle, the weaker the amount of
energy.
High Angle – Sun is directly overhead
High Angle – Sun is directly overhead with high intensity of energy - short shadows
LOW ANGLE – Sun is low in the sky –low intensity of energy
LOW ANGLE – Long shadows, lower intensity of Sun’s energy
IMPORTANT DATES
• JUNE 21: SUMMER SOLSTICE• DECEMBER 21: WINTER SOLSTICE• MARCH 21: VERNAL EQUINOX• SEPTEMBER 21: AUTUNM EQUINOX
IMPORTANT LATITUDES
• ZENITH – POINT DIRECTLY ABOVE• JUNE 21 – 23.5 NORTH (Tropic of Cancer)• DECEMBER 21 – 23.5 SOUTH (Tropic of Capricorn)• MARCH 21 & SEPTEMBER 21 - 0 (Equator)
SUN’S PATH
SUN’S PATH
SHADOWS
• In New York– Sun’s Path is always in the southern sky.
• Shadows are always opposite the Sun• Low Sun, Long shadows• High Sun, short shadows
SHADOWS
High Noon, December 11 at Reykjavik
High Sun, Short Shadows