Abstract Details

Name: Govind Nampoothiri
Affiliation: Space Physics Laboratory
Conference ID: ASI2021_211
Title : Electron velocity distrubtion functons at 1 AU during the halo CME event on 25 July 2004
Authors and Co-Authors : Govind G Nampoothiri, R Satheesh Thampi, J K Abhishek, Smitha V Thampi, Tarun K pant (Space Physics Laboratory, VSSC, ISRO, Trivandrum-695022)
Abstract Type :
Abstract Category : Sun and the Solar System
Abstract : In this paper, we analysed the kinetic properties of the electron velocity distribution functions during the passage of a halo Coronal Mass Ejection (CME) using in situ measurements from the plasma analyzers at 1 AU. The halo CME erupted on 25 July 2004 (Carrington rotation 2019) from the active region NOAA AR 10652 (N04W30) and the ICME reached at the L1 point 31 hrs after the eruption. Solar wind electron data from three dimensional plasma instrument (3DP) on board WIND spacecraft and the CME data from Large Angle and Spectroscopic Coronograph (LASCO) on board solar and heliospheric observatory (SOHO) have been used for performing the present study. ENLIL with cone, A time dependant 3-dimensional Magnetohydrodynamic model by Community Coordinated Modelling Center (CCMC)is also used to simulate the evolution of the ICME through the heliosphere. The velocity distributions of electrons observed at the L1 point, show distinct features representing the passage of the ICME plasma and the associated magnetic cloud. Relative to the ambient solar wind condition, the suprathermal halo electron populations were enhanced more than that of the core electron populations. Following the CME's forward shock and sheath plasma, a bi-directional electron streaming (bi-directional strahl electrons) representing a possibly closed magnetic flux rope is observed. The non-equilibrium Boltzmann entropy analysis of the event shows an enhanced entropy along the bi-directional electron streaming, parallel to the magnetic field.