Expert: Courtney Seligman - 6/18/2009

Question
Hi, I have a question about the ecliptic.

What are the times or dates during the year when a place on the equator receives the maximum daily amount of solar radiation and the least daily. Is it during a solstice or during the equinox. I'm confused because the equinox is equal 12 of sunlight and 12 of night. But it says solar radiation, is that sinlight?? Please help! =)


Answer
At the Equator, there are 12 hours of sunlight and 12 hours of night every day, throughout the year. So the length of the day isn't affected by the Equinoxes or Solstices, at that latitude. What is affected is the amount of sunlight received during the 12 hours of daylight. Near the Equinoxes (the start of Spring and Fall), the Sun is near the Celestial Equator, and would pass nearly overhead at the Equator. This would give you the maximum radiation per day. Near the Solstices (the start of Summer and Winter), the Sun is as far from the Celestial Equator as possible, and is about 23 degrees away from overhead at its highest. This would give you the least amount of radiation per day.