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Geosciences LibreTexts

2: Solar and Infrared Radiation

  • Page ID
    9539
  • Solar energy powers the atmosphere. This energy warms the air and drives the air motion you feel as winds. The seasonal distribution of this energy depends on the orbital characteristics of the Earth around the sun. The Earth’s rotation about its axis causes a daily cycle of sunrise, increasing solar radiation until solar noon, then decreasing solar radiation, and finally sunset. Some of this solar radiation is absorbed at the Earth’s surface, and provides the energy for photosynthesis and life. Downward infrared (IR) radiation from the atmosphere to the Earth is usually slightly less than upward IR radiation from the Earth, causing net cooling at the Earth’s surface both day and night. The combination of daytime solar heating and continuous IR cooling yields a diurnal (daily) cycle of net radiation.

    Thumbnail: Note the two smaller eruptions before the big one. The Sun’s upper atmosphere (corona) is shown here. (CC BY-SA 3.0 Unported; Patrick McCauley/From Quarks to Quasars/SDO via Wikipedia).