Original Paper

You have free access to this content

The statistical study of quasi-periodic oscillations of the radio emission in solar quiet regions

  1. J. Kallunki1,2,*,
  2. A. Riehokainen2

Article first published online: 12 JAN 2012

DOI: 10.1002/asna.201111630

Issue

Astronomische Nachrichten

Astronomische Nachrichten

Volume 333, Issue 1, pages 20–25, January 2012

Additional Information

How to Cite

Kallunki, J. and Riehokainen, A. (2012), The statistical study of quasi-periodic oscillations of the radio emission in solar quiet regions. Astron. Nachr., 333: 20–25. doi: 10.1002/asna.201111630

Author Information

  1. 1

    Aalto University, Metsähovi Radio Observatory, Kylmälä, Finland

  2. 2

    University of Turku, Tuorla Observatory, Kaarina (Piikkiö), Finland

*Aalto University, Metsähovi Radio Observatory, Kylmälä, Finland

Publication History

  1. Issue published online: 12 JAN 2012
  2. Article first published online: 12 JAN 2012
  3. Manuscript Accepted: 3 NOV 2011
  4. Manuscript Received: 28 JUN 2011

Funded by

  • project of international cooperation between ESA and NASA

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

Get PDF (225K)

Keywords:

  • Sun: activity;
  • Sun: oscillations;
  • Sun: radio radiation;
  • methods: data analysis;
  • methods: statistical

Abstract

In this study we discuss variations of the radio emission from the Quiet Sun Areas (QSA) at centimeter wavelength (1.76 cm). Data were obtained from Nobeyama Radioheliograph (NoRH). Oscillations of selected areas were studied carefully from data taken over one week. We try to find quasi-periodic solar oscillations from the QSA. We used the traditional Fast Fourier Transform (FFT), Global Wavelet Spectrum (GWS) and Wavelet (Morlet) for studying signals in the frequency/time-frequency domain. We used the Fisher randomization test to verify the significance of the observed signal. Instrumental and sky noises were studied using a cross-correlation analysis. Additionally, a single pixel analysis were done. Wide ranges of solar oscillation periods were found from the Quiet Sun Area (QSA): 3–15, 35–70, and 90 minutes. Some physical explanations are suggested for these oscillations. However, it is not possible to give a conclusive statement about the origin of the long quasi-periodic (>60 min) oscillations from the QSA (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Get PDF (225K)