Solar radio type-I noise storm modulated by coronal mass ejections

K. Iwai, Y. Miyoshi, S. Masuda, M. Shimojo, D. Shiota, S. Inoue, F. Tsuchiya, A. Morioka, H. Misawa

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65° (ahead) and -70° (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

Original languageEnglish (US)
Article number167
JournalAstrophysical Journal
Issue number2
StatePublished - Jan 10 2012
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Sun: corona
  • Sun: coronal mass ejections (CMEs)
  • Sun: magnetic topology
  • Sun: radio radiation


Dive into the research topics of 'Solar radio type-I noise storm modulated by coronal mass ejections'. Together they form a unique fingerprint.

Cite this