skip to main content

Title: ON THE VARIATION OF SOLAR RADIUS IN ROTATION CYCLES

The Date Compensated Discrete Fourier Transform and CLEANest algorithm are used to study the temporal variations of the solar radius observed at Rio de Janeiro Observatory from 1998 March 2 to 2009 November 6. The CLEANest spectra show several significant periodicities around 400, 312, 93.5, 86.2, 79.4, 70.9, 53.2, and 26.3 days. Then, combining the data on the daily solar radius measured at Calern Observatory and Rio de Janeiro Observatory and the corresponding daily sunspot areas, we study the short-term periodicity of the solar radius and the role of magnetic field in the variation of the solar radius. The rotation period of the daily solar radius is determined to be statistically significant. Moreover, its temporal evolution is anti-phase with that of sunspot activity, and it is found anti-phase with solar activity. Generally, the stronger solar activity is, the more obvious is the anti-phase relation of radius with solar activity. This indicates that strong magnetic fields have a greater inhibitive effect than weak magnetic fields on the variation of the radius.
Authors:
; ;  [1] ;  [2]
  1. Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)
  2. Research Center of Analysis and Measurement, Kunming University of Science and Technology, Kunming 650093 (China)
Publication Date:
OSTI Identifier:
22364623
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 798; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALGORITHMS; C CODES; COMPUTERIZED SIMULATION; EMISSION SPECTRA; FOURIER TRANSFORMATION; MAGNETIC FIELDS; PERIODICITY; ROTATION; SUN; SUNSPOTS