Solar Physics

, Volume 267, Issue 2, pp 295–303

Periodicity of Total Solar Irradiance


    • National Astronomical Observatories/Yunnan ObservatoryCAS
    • Key Laboratory of Solar Activity, National Astronomical ObservatoriesCAS
  • J. C. Xu
    • National Astronomical Observatories/Yunnan ObservatoryCAS
    • Graduate School of CAS
  • X. H. Liu
    • Department of PhysicsJiaozuo Advanced Normal College
  • P. X. Gao
    • National Astronomical Observatories/Yunnan ObservatoryCAS
    • Graduate School of CAS
  • L. S. Zhan
    • Jingdezhen Ceramic Institute

DOI: 10.1007/s11207-010-9655-8

Cite this article as:
Li, K.J., Xu, J.C., Liu, X.H. et al. Sol Phys (2010) 267: 295. doi:10.1007/s11207-010-9655-8


We investigate the periodicity in the PMOD composite of the daily total solar irradiance (TSI) from 21 September 1978 to 9 June 2009. Besides the Schwabe cycle period (10.32 years), the quasi-rotation period is found to be statistically significant in TSI, whose value is about 32 days, longer than that in sunspot activity (27 days), and it intermittently appears around the sunspot maximum times. The quasi-rotation period in TSI is inferred to be mainly caused by sunspot activity, but to be modulated by bright features as well. It was previously found that variations of TSI over a Schwabe solar cycle mainly come from the combination of the sunspots’ blocking and the intensification due to bright faculae, plages, and network elements, with a slight dominance of the bright-feature effect during the maximum of the Schwabe cycle. For the sunspot-blocking and the bright-feature effect to contribute to TSI over a Schwabe solar cycle, the former is inferred to lead the latter by 29 days at least.


Solar irradianceSolar cycleObservations

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© Springer Science+Business Media B.V. 2010