THE LONGITUDINAL PROPERTIES OF A SOLAR ENERGETIC PARTICLE EVENT INVESTIGATED USING MODERN SOLAR IMAGING
- Institut de Recherche en Astrophysique et Planetologie, Universite de Toulouse (UPS), Toulouse (France)
- Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)
- College of Science, George Mason University, Fairfax, VA 22030 (United States)
- Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)
- Applied Physics Laboratory, John Hopkins University, Laurel, MD 20723 (United States)
- Institute for Physical Science and Technology, University of Maryland, Greenbelt, MD 20742 (United States)
- University Corporation for Atmospheric Research, Boulder, CO 80307 (United States)
- Heliophysics Science Division, Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
We use combined high-cadence, high-resolution, and multi-point imaging by the Solar-Terrestrial Relations Observatory (STEREO) and the Solar and Heliospheric Observatory to investigate the hour-long eruption of a fast and wide coronal mass ejection (CME) on 2011 March 21 when the twin STEREO spacecraft were located beyond the solar limbs. We analyze the relation between the eruption of the CME, the evolution of an Extreme Ultraviolet (EUV) wave, and the onset of a solar energetic particle (SEP) event measured in situ by the STEREO and near-Earth orbiting spacecraft. Combined ultraviolet and white-light images of the lower corona reveal that in an initial CME lateral 'expansion phase', the EUV disturbance tracks the laterally expanding flanks of the CME, both moving parallel to the solar surface with speeds of {approx}450 km s{sup -1}. When the lateral expansion of the ejecta ceases, the EUV disturbance carries on propagating parallel to the solar surface but devolves rapidly into a less coherent structure. Multi-point tracking of the CME leading edge and the effects of the launched compression waves (e.g., pushed streamers) give anti-sunward speeds that initially exceed 900 km s{sup -1} at all measured position angles. We combine our analysis of ultraviolet and white-light images with a comprehensive study of the velocity dispersion of energetic particles measured in situ by particle detectors located at STEREO-A (STA) and first Lagrange point (L1), to demonstrate that the delayed solar particle release times at STA and L1 are consistent with the time required (30-40 minutes) for the CME to perturb the corona over a wide range of longitudes. This study finds an association between the longitudinal extent of the perturbed corona (in EUV and white light) and the longitudinal extent of the SEP event in the heliosphere.
- OSTI ID:
- 22037079
- Journal Information:
- Astrophysical Journal, Vol. 752, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
The solar energetic particle event on 2013 April 11: an investigation of its solar origin and longitudinal spread
PROPERTIES OF A CORONAL SHOCK WAVE AS A DRIVER OF EARLY SEP ACCELERATION