Auroral zone X-ray pulsations associated with VLF pulsations: B15-3N balloon experiment

概要

論文の詳細を見る
A stratospheric balloon, carrying a Nal (T1) scintillation counter for measuring 20-100keV bremsstrahlung X-rays was launched from Stamsund (L=5.6) in Norway during the recovery phase of a magnetic substorm. The scintillation counter recorded many examples of X-ray microbursts and pulsations at a ceiling altitude of 7mb (33km). The ground-based VLF receiver at Andφya (L=6.1), located at 160km northeast of Stamsund, and at Syowa Station, Antarctica (L=6.1) observed polar chorus emissions and quasi-periodic (QP) emissions during the balloon flight. In the study of cross correlations between the X-ray and the VLF emissions, it has been found that the X-ray microbursts precede VLF chorus at Andφya by about 1.7s, while the VLF chorus at Syowa occurred almost simultaneously with the X-ray microbursts. This is qualitatively explained by the nature of counterstreaming type wave-particle interaction and the echoing of whistler mode wave packets in the magnetosphere. X-ray pulsations and rising-tone type QP emissions with periods of 20-30s showed a good coherency. This similarity suggests that both phenomena are closely related to each other through the cyclotron wave-particle interaction in the magnetosphere.
国立極地研究所の論文