Aim: How is INSOLATION described? Do Now: What is the least and the most hours of daylight during the year?

What is INSOLATION? Insolation- solar radiation (energy from the sun) that interacts with our atmosphere, hydrosphere, and lithosphere. INcoming SOLar radiATIONInsolation- solar radiation (energy from the sun) that interacts with our atmosphere, hydrosphere, and lithosphere. INcoming SOLar radiATION

Most of the insolation that the Earth receives at the surface is in the form of visible light.

How does the Earth’s atmosphere affect Insolation? Most incoming ultraviolet radiation and other shortwave radiation are absorbed by the atmosphere. Most U-V is absorbed by the ozone (O3) layer found in the stratosphere. The longer waves such as infrared radiation (heat) are absorbed by other gases such as carbon dioxide (CO2), methane, and water vapor. This warms the atmosphere.

Clouds in the lower atmosphere (Troposphere) reflect insolation back out into space.Clouds in the lower atmosphere (Troposphere) reflect insolation back out into space. Insolation can be scattered by gases and aerosols (pollutants), example - O2 scatters the blue portion of visible light making the sky appear blue, aerosols and other gases cause sunsets.Insolation can be scattered by gases and aerosols (pollutants), example - O2 scatters the blue portion of visible light making the sky appear blue, aerosols and other gases cause sunsets.

What is meant by radiative balance? The amount of insolation absorbed by the Earth’s atmosphere and surface over time is equal to the amount of reradiation produced by the Earth.

What factors affect of insolation? The angle of insolation. The duration of insolation. The nature of the Earth’s surface. Change of phase and photosynthesis.

Angle of INSOLATION The Earth is a sphere and insolation does not strike the Earth’s surface at the same angle at different locations. Latitude – At the equator insolation strikes it directly but at the poles insolation comes in at an angle.

Direct insolation (high angle 90°) is absorbed more and indirect (low angle <30°) is reflected.

Duration of INSOLATION The duration of insolation is the amount of time the sun is out, this changes with season and latitude.The duration of insolation is the amount of time the sun is out, this changes with season and latitude. At 41°N (NYC) on Dec.21 st the duration = 9hrs on June 21 st the duration = 15hrs.At 41°N (NYC) on Dec.21 st the duration = 9hrs on June 21 st the duration = 15hrs.

Nature of the Earths surface The Earth’s surface is made of many different materials and the insolation received reacts differently because of TEXTURE and COLOR.

Phases and Photosynthesis Insolation that is used to change the phase of a material does not raise the temperature (latent heat).Insolation that is used to change the phase of a material does not raise the temperature (latent heat). Plants use insolation to live (photosynthesis) and this does not raise Earth’s temperature.Plants use insolation to live (photosynthesis) and this does not raise Earth’s temperature.

How does the greenhouse effect work? Shortwave insolation from the sun is absorbed at the surface and the surface reradiates a longer wave (infrared). Infrared radiation is absorbed by greenhouse gases such as CO2, methane, and water vapor which warms the atmosphere.