Flashlights on Earth ELF Activity: Energy 1A As part of NOAA Environmental Literacy Grant #NA09SEC to the University of Nebraska–Lincoln's, ANDRILL Science Management Office. This material is based on work supported by an Environmental Literacy Grant from the National Oceanic and Atmospheric Administration's Office of Education (NA0909SEC ) and prior work supported by the National Science Foundation under Grants ANT and ESI Any opinions, findings, and conclusions or recommendations expressed in these materials are those of the authors and do not necessarily reflect the views of the NOAA or the NSF.

One could say that we live on a solar-powered planet. The solar radiation that reaches Earth’s surface is the energy that drives many of the processes acting on the surface of the Earth, including photosynthesis, wind, ocean currents, weather, and climate. Earth: The Solar-Powered Planet

INcoming SOLar radiATION=INSOLATION What Is Solar Insolation?

The Sun! The Sun’s energy travels to Earth in the form of electromagnetic radiation. Solar energy travels 93 million miles (150 million kilometers) through space from the Sun to the Earth. Because of the distance that it travels, solar radiation arrives at Earth’s surface in essentially parallel lines. Where Does the Solar Energy Come From?

How Is Solar Energy Distributed across the Earth’s Surface? Because the Earth is a sphere, the rays of light from the Sun strike Earth’s surface at different angles. The equatorial regions of the Earth receive light that is nearly perpendicular to the surface (90˚), while the regions nearer the poles receive light that is at an angle of less than 30˚ from the surface.

Why Is It Colder at the Poles? The greater the angle of incoming light, the more the incoming solar radiation is spread over a larger area, decreasing its intensity. Spreading the radiation over a larger area reduces the intensity of light in any one place.

Average Incoming Solar Radiation The area around the Equator receives the most sunlight year-round. Note areas of high (pink) and low (blue) insolation.

In this lab you will examine the differences in solar intensity at a variety of angles. You will see first-hand how the solar intensity changes as the light is spread over a larger area.

This material is based on work supported by an Environmental Literacy Grant from the National Oceanic and Atmospheric Administration’s Office of Education (NA09SEC ) and prior work supported by the National Science Foundation under Grants ANT and ESI Any opinions, findings, and conclusions or recommendations expressed in these materials are those of the authors and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration or the National Science Foundation.