WHY IS THE SOLAR CONSTANT NOT A CONSTANT?

Journal Article · Sat Mar 10 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/747/2/135· OSTI ID:22016246

Li, K J; Xu, J C; Gao, P X; Yang, L H ^[1]; Feng, W ^[2]; Liang, H F ^[3]

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1. National Astronomical Observatories/Yunnan Observatory, CAS, Kunming 650011 (China)
2. Research Center of Analysis and Measurement, Kunming University of Science and Technology, Kunming 650093 (China)
3. Department of Physics, Yunnan Normal University, Kunming 650093 (China)

In order to probe the mechanism of variations of the solar constant on the inter-solar-cycle scale, the total solar irradiance (TSI; the so-called solar constant) in the time interval of 1978 November 7 to 2010 September 20 is decomposed into three components through empirical mode decomposition and time-frequency analyses. The first component is the rotation signal, counting up to 42.31% of the total variation of TSI, which is understood to be mainly caused by large magnetic structures, including sunspot groups. The second is an annual-variation signal, counting up to 15.17% of the total variation, the origin of which is not known at this point in time. Finally, the third is the inter-solar-cycle signal, counting up to 42.52%, which is inferred to be caused by the network magnetic elements in quiet regions, whose magnetic flux ranges from (4.27-38.01) Multiplication-Sign 10{sup 19} Mx.

• OSTI ID: 22016246
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 747; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNUAL VARIATIONS
FREQUENCY ANALYSIS
MAGNETIC FLUX
RADIANT FLUX DENSITY
ROTATION
SIGNALS
SOLAR CONSTANT
SOLAR CYCLE
SUN
SUNSPOTS