Aim: How can we explain insolation?

What’s different? Sun’s Rays

Insolation INcoming SOLar radiATION The sun’s energy that reaches Earth

Rays of light from the Sun that hit Earth are parallel NOTE: NOT TO SCALE!!!! Rays of light from the Sun that hit Earth are parallel

Factors Affecting the INTENSITY of insolation Wavelength Angle Duration

1. Wavelength Infrared Visible Ultraviolet

ESRT Find the page of your ESRT that deals with wavelength.

Which wavelength is most intense? Intensity of Insolation VISIBLE INFRARED UV Visible 7% is UV 44% is visible 48% is infrared Increasing Wavelength

2. Angle The angle at which radiation strikes the Earth’s surface The larger the angle, the higher the intensity

Rays less concentrated, more spread out Rays very concentrated Flashlight Example 90o 30o Rays less concentrated, more spread out LOW intensity Rays very concentrated HIGH intensity

Angle affected by three factors: a) Time of Day b) Latitude (shape of Earth) c) Season

a) Time of Day The sun is the highest at NOON  rays most direct, angle of insolation is the highest Sun’s rays most spread out at SUNRISE and SUNSET

Less concentrated, LOW intensity More concentrated, HIGHEST intensity Sun at noon Sun at sunrise E W Less concentrated, LOW intensity More concentrated, HIGHEST intensity

b) Latitude (shape of Earth) Because of Earth’s shape, rays hit different latitudes at different angles Hitting at 30o 8oC Hitting at 90o 27oC

c) Season The path of the sun in our sky changes during the year, resulting in changes in the angle of insolation

SUN’s rays at NOON for NYC December 21st March 21st and Sept. 23rd June 21st Winter Summer Spring and Fall 48o 71.5o 24.5o Low angle of insolation Low intensity Average angle of insolation Average intensity High angle of insolation Highest intensity

3. Duration The length of time (sunrise to sunset) the sun is in the sky For NYS: Longest on June 21st Shortest of December 21st Long duration = HIGH intensity As angle , temperature As duration , temperature

Suface Objects and Insolation Objects that are DARK in color tend to absorb the heat from the sun Objects that are LIGHT in color tend to reflect heat. Rough object absorb more heat than smooth object.

The length of time that daylight is received at a location during one day is called the location’s Angle of insolation Intensity of insolation Duration of insolation Eccentricity of insolation

The diagram below represents a portion of Earth’s surface that is receiving insolation. Positions A, B, C, and D are located on Earth’s surface. At which position would the intensity of insolation be greatest? A B C D

As the altitude of the Sun increases, the length of the shadow cast by a vertical pole will Decrease Increase Remain the same

The coldest climates on Earth are found at the polar regions because the polar regions Absorb the most insolation Are usually farthest from the Sun Receive the shortest duration of insolation Receive the lowest angle of insolation

What happens to the angle of insolation on June 21st between solar noon and 6 p.m. in New York State? It decreases steadily In increases steadily It remains the same If first increases and then decreases

In which diagram does the incoming solar radiation reaching the Earth’s surface have the greatest intensity?