Total Solar Irradiance Data in Solar Studies
Total solar irradiance measurements made by ACRIM will also provide solar physicists with information about the interior of the sun. Imagine that the sun is a ball of fluid (like JELLO) hanging in space. Now imagine the ball of JELLO wiggling, or oscillating. Physicists describe these oscillations as two different types - pressure mode (caused by pressure forces in the sun’s outer atmosphere) and gravity mode (caused by gravitational forces outside of the sun). These oscillations, or waves, travel through the sun and can provide information about its interior. Using the periods (repetitive cycles) of these oscillations, solar physicists hope to gain information about the underlying layers of the sun that cannot be detected by other methods.

The ACRIMSAT mission is funded by NASA through the Earth Science Programs Office at Goddard Space Flight Center. The ACRIM III experiment is under the direction of Dr. Richard Willson and his science team at Columbia University. The ACRIMSAT Project Office at the Jet Propulsion Laboratory (Pasadena, CA) manages the design, fabrication, and test of the ACRIM III instrument and manages the subcontract for the ACRIMSAT spacecraft being built by Orbital Sciences Corporation. The ACRIM III data products are available through the Langley Distributed Active Archive Center and the ACRIM III Science Team website

Additional information on the ACRIMSAT mission can be found at and

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Variations in Total Solar Irradiance
Total Solar Irradiance Data in Climate Studies
Total Solar Irradiance Data in Solar Studies

Related Data Sets
Outgoing Longwave Radiation

Related Sites
ACRIM Instruments