Radial evolution and turbulence characteristics of a coronal mass ejection

We investigate a coronal mass ejection (CME) associated with an X3.9 solar flare that occurred on 1992 June 25. This long-duration event showed a syst em of large postflare loops at the activity site throughout the period of t he enhanced X-ray emission. The drift rate of the metric type IV radio burs t observed near the X-ray maximum suggests the speed of the ejecta to be si milar to 350 km s(-1) at heights less than or equal to 2 solar radii. The s olar proton intensities, in the energy range 1-100 MeV observed in the inte rplanetary medium, show gradual-decay profiles lasting for more than two da ys and suggest CME-driven acceleration near the Sun. The inference on the s patial and kinematical characteristics of the propagating CME in the inner heliosphere (0.2-1 AU) is primarily based on the interplanetary scintillati on observations at 327 MHz, obtained from the Ooty Radio Telescope and the Solar-Terrestrial Environment Laboratory. The scintillation data show the d eceleration of propagating disturbance speed, V-CME similar to R-0.8, in th e interplanetary medium. The speeds obtained from the radio and scintillati on measurements also suggest that the coronal shock may not be directly rel ated to the interplanetary shock. The size of the CME in the interplanetary medium seems to follow a simple scaling with distance from the Sun, indica ting the pressure balance maintained between the ejecta and the ambient sol ar wind. The density turbulence spectrum of the plasma carried by the propa gating disturbance seems to be flat, Phi(Ne(IPD)) similar to kappa(-2.8), a lso having a small dissipative scale length, S-i(IPD) less than or equal to 5 km The spectrum is significantly different from that of high-speed flow from coronal holes and low-speed wind originating above closed-held coronal streamers.