[P-EM27_1PM2] Heliosphere and Interplanetary Space

[PEM27-01] Micro-TypeIII radio bursts and outer corona

*Akira MORIOKA¹, Yoshizumi MIYOSHI², Yasumasa KASABA³, Satoshi MASUDA², Kazumasa IWAI⁴, Hiroaki MISAWA¹ (1.PPARC, Tohoku University, 2.STEL, Nagoya University, 3.Dep. of Gephys. Tohoku University, 4.NSRO, NAOJ)

Keywords:micro-type-III burst, outer corona, solar radio burst, interplanetary space, inner-heliosphere

We presents detailed features of micro-typeIII radio bursts and its relation to the outer corona, by using long-term observations made by the Geotail satellites. Micro-typeIII radio bursts are elements of the so-called type III storm, and are characterized by short-lived, continuous, and weak emissions. Their average power is estimated to be well below that of the largest type III burst by 6 orders of magnitude. The activity of micro-typeIII bursts with respect to the solar activity, lower frequency limit of the bursts and its relation to the solar activity, and the configuration of magnetic field line of which source electrons are trapped are investigated. The relationship between streamers and micro-typeIII bursts are discussed by using STEREO observations.