1. Call For Abstracts for an SEP session at the 2016 SHINE workshop
Session : Understanding the Origin and Transport of GLEs with Modern Observations
Convenors: Georgia de Nolfo, Jim Ryan, and Gen Li, and Eric Christian
How the highest energy solar energetic particles, the so called Ground Level Enhancements (GLEs) are accelerated to GeV energies remains a mystery. Both acceleration through flare reconnection and CME-driven shocks are plausible, but the question remains as
to their relative importance in driving the highest energy SEP events. While these high-energy particles often reach near Earth with minimal transport effects compared to the widely studied low-energy SEPs, the spectral shape, anisotropy, and time-evolution
of GLEs suggest that transport is important in interpreting these events. This session will focus on the origin and transport of the highest energy (>100 MeV) particles in SEP events, with a focus on GLEs and high-energy SEP events that may fail to register
in neutron monitors, the so-called sub-GLEs (e.g. Jan 6 2014, Jan 27 2012).
Solar cycle 24 has provided an unprecedented view of GLE events including the first spectral and pitch angle measurements of GLEs over a wide range in energy from PAMELA and AMS, complementing the observations of traditional ground-based instruments. In addition,
multi-point observations from spacecraft at 1 AU and the STEREO spacecraft provide detailed contextual data, particularly on CME structure and evolution and potential magnetic connectivity. While solar cycle 24 brings excited new observations to shed light
on the GLE process, we welcome discussions on high-energy events from previous solar cycles.
Our session will expand on the discussion from SHINE 2015, focusing on the following questions:
•
What is the spectral shape (and its evolution) over a broad energy range and how does this constrain models of acceleration? Are there spectral roll-overs, breaks?
•
Is there a relationship between the anisotropic phase and it's evolution with time and the spectral shape (and its evolution)?
•
Do all GLEs exhibit an anisotropic phase? What about sub-GLEs? Isotropy at later times appears to be universal.
•
What spectral features and/or pitch angle differences do we expect between GLE events that are well-connected. such as 2012 May 17, and other events (not necessarily GLEs) originating from the eastern hemisphere, e.g., 2012 March 7?
•
Several of the GLEs in cycle 24 are associated with high-energy gamma-ray observations from Fermi/LAT. How or do the gamma-ray observations influence our understanding of GLE particle acceleration? Are the particles in the flare and those in space related,
and how?
SHINE 2016
Workshop Dates: July 21st-25th, 2016
(Student Day August 20th)
Location: Santa Claus, New Mexico
Early Bird Registration Fee: $425
Early Bird Registration Deadline: May 20th
Late Registration: $475
Deadline for student support: April 29st
Deadline for abstract submission: June 9th
Hotel Reservation Deadline: June 9th
Georgia de Nolfo
NASA/Goddard Heliospheric Physics Division
Greenbelt, MD, 20771
301-286-1512