Decameter U-burst Harmonic Pair from a High Loop

作者：Dorovskyy V V^*; Melnik V N; Konovalenko A A; Bubnov I N; Gridin A A; Shevchuk N V; Rucker H O; Poedts S; Panchenko M

来源：Solar Physics, 2015, 290(1): 181-192.

DOI：10.1007/s11207-014-0615-6

• Corona, radio emission
• Corona, structures
• Radio bursts, meter-wavelengths and longer (m, dkm, hm, km)
• Radio bursts, type U
• Radio bursts, harmonic pairs

The results of the first observations of solar sporadic radio emission within 10 -aEuro parts per thousand 70 MHz by the Giant Ukrainian Radio Telescope (GURT) are presented and discussed. Observations in such a wide range of frequencies considerably facilitate the registration of harmonic pairs. The solar U-burst harmonic pair observed on 8 August 2012 is analyzed. The burst key features were determined. Among them, the time delay between the fundamental and harmonic emissions was of special interest. The fundamental emission was delayed for 7 s with respect to the harmonic emission. A model for explaining the occurrence of such a delay is proposed, in which the emission source is located inside a magnetic loop containing plasma of increased density. In this case, the delay appears due to the difference in group velocities of electromagnetic waves at the fundamental and the harmonic frequencies.

• 出版日期2015-1