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 Shadows are always opposite the Sun 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 Sun does not rise much above the horizon during this time of year.

High Sun, Short Shadows