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Glory TIM Science

Total solar irradiance (TSI) is the dominant driver of the global temperature of the Earth. The climate of the Earth is almost completely determined by the balance between the intensity of the solar radiation and the response of the Earth's atmosphere via absorption, reflection, and re-radiation. Changes in either the solar irradiance or the composition of the atmosphere can cause climate change. Solar irradiance is a purely natural phenomenon, while the composition of the atmosphere is influenced by both natural and anthropogenic effects such as the byproducts of modern industrial societies. Over the past century the average temperature at the Earth's surface has increased by approximately 0.5 degree Celsius. Attributing the portions of this increase and the concomitant climate change due to natural events and anthropogenic sources is of primary importance to the establishment of scientifically and economically effective policy.

The continued measurement of the TSI to determine the Sun's direct and indirect effects on Earth's climate, at current state-of-the-art accuracy and without temporal gaps in the dataset, constitutes the solar irradiance requirement for the Glory mission and the objective of the Total Irradiance Monitor (TIM) instrument. It is essential that there be no temporal gaps in the multi-decadal measurement record of the TSI, as any measured changes in the atmospheric temperature must be appropriately interpreted in the context of solar irradiance variations.

The Glory/TIM continues what will be, at the time of launch in March 2011, an uninterrupted 32-year record of TSI measurements. This instrument is a rebuild of the successful SORCE/TIM launched in early 2003.


Kopp, G., and J. L. Lean, 2011: A new, lower value of total solar irradiance: evidence and climate significance, Geophys. Res. Letters 38, L01706.
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Kopp, G., K. Heuerman, D. Harber, and V. Drake, 2007: The TSI Radiometer Facility - absolute calibrations for total solar irradiance instruments, Proc. SPIE 6677, 667709.
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Harber, D.M., K. F. Heuerman, G. A. Kopp, and G. Lawrence, 2006: Aperture edge scatter calibration of the cavity radiometers for the spaceflight Total Irradiance Monitor, Proc. SPIE 6296, 62961I.
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Heuerman, K., D. Harber, A. Ebbets, G. Kopp, and L. Logan, 2006: Calibration of the absorptance cavities for the spaceflight solar radiometer TIM, Proc. SPIE 6296, 62961H.
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Woods, T.,V. George, J. Harder, G. Kopp, B. McClintock, P. Pilewskie, and M. Snow, 2006: Solar irradiance variability during the SORCE Mission, Earth Observer, July-Aug.

Lean, J., G. Rottman, J. Harder, and G. Kopp, 2005: Sorce contributions to new understanding of global change and solar variability, Solar Phys. 230, 27-53.
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Kopp, G., and G. Lawrence, 2005: The Total Irradiance Monitor (TIM): Instrument design. Solar Phys. 230, 91-109.
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Kopp, G., K. Heuerman, and G. Lawrence, 2005: The Total Irradiance Monitor (TIM): Instrument calibration. Solar Phys. 230, 111-127.
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Kopp, G., G. Lawrence, and G. Rottman, 2005: The Total Irradiance Monitor (TIM): Science results. Solar Phys. 230, 129-139.
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Kopp, G., G. Lawrence, and G. Rottman, 2004: The Total Irradiance Monitor design and on-orbit functionality, Proc. SPIE 5171, 14-25.
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Lawrence, G.M., G. Kopp, G. Rottman, J. Harder, T. Woods, and H. Loui, 2003: Calibration of the Total Irradiance Monitor, Metrologia 40, S78-S80.
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Lawrence, G.M.,G. Rottman, G. Kopp, J. Harder, W. McClintock, and T. Woods, 2000: The Total Irradiance Monitor (TIM) for the EOS SORCE Mission, Proc. SPIE 4135, 215-224.
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TIM Science Team

Greg Kopp
TIM Instrument Scientist
Laboratory for Atmospheric and Space Physics
University of Colorado
1234 Innovation Drive
Boulder, CO 80303-7814
Phone: (303) 735-0934

Team Members

Claus Fröhlich
Judith Lean
Joe Rice
Rodney Viereck
Dick White