Solar Variability and Total Solar Irradiance (TSI)
Released on February 19, 2009
Analyzing the Sun and its effects on climate is complicated by the fact that the amount of radiation arriving from the Sun is not constant. It varies from the average value of the total solar irradiance (TSI)—1,361 W/m2—on a daily basis. Variations in TSI are due to a balance between decreases caused by sunspots and increases caused by faculae, which are the bright areas that surround sunspots. The Sun's energy output varies with time, and Glory's TIM instrument will help measure those fluctuations by continued monitoring of TSI. Data from TIM will extend the long-term climate record, which has been uninterrupted since 1978 and provides the best estimate available of solar inputs to climate. This short movie displays the Sun rotating and the corresponding total solar irradiance.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 18.104.22.168.0