The effects of coronal mass ejection on galactic cosmic rays in the high latitude heliosphere: Observations from Ulysses` first orbit
- Univ. of Kiel (Germany). Institut fuer Kernphysik
- Los Alamos National Lab., NM (United States)
- Imperial College, London (United Kingdom). Blackett Lab.
- CEA, Gif-sur-Yvette (France). Service d`Astrophysique
- Univ. di Milano (Italy). Istituto di Fisica Cosmica CNR
During its first solar orbit the Ulysses spacecraft detected several coronal mass ejections (CMEs) at high heliographic latitudes. The authors present first observations on the effects of these high latitude CMEs on galactic cosmic rays (GCRs) using measurements from the Kiel Electron Telescope (KET) which is part of the Cosmic Ray and Solar Particle Investigation (COSPIN) experiment, the Los Alamos SWOOPS (Solar Wind Observations Over the Poles of the Sun) experiment and the magnetic field experiments. They find the passage of these CMEs over the spacecraft to be associated with short term decreases of GCR intensities The relatively weak shocks in these events, driven by the CMEs` over-expansion, had no strong influence on the GCRs. The intensity minimums of GCRs occurred on closed magnetic field lines inside the CMEs themselves as indicated by bidirectional fluxes of suprathermal electrons. Short episodes of intensity increases of GCRs inside CMEs at times when the bidirectional fluxes of suprathermal electrons disappeared, can be interpreted as evidence that GCRs can easily access the interior of those CMEs in which open magnetic field lines are embedded.
- Research Organization:
- Los Alamos National Lab., NM (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Management and Administration, Washington, DC (United States); Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA) GmbH, Bonn (Germany)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 642769
- Report Number(s):
- LA-UR--97-2669; CONF-9707103--; ON: DE98000817; CNN: Grant 50 ON 9106
- Country of Publication:
- United States
- Language:
- English
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