NSF Award
1460118
This 3-year collaborative SHINE project is expected to: (1) advance basic understanding of how charged particles are accelerated in the inner heliosphere; (2) yield new information about the properties of suprathermal (ST) ions in the inner heliosphere; and, (3) provide a sound basis for enabling broader theoretical investigations involving acceleration of ST and energetic ions at a variety of astrophysical sites. The outcome of the project is expected to significantly improve basic understanding of a fundamental problem in space plasma physics namely, how charged particles are injected and accelerated at shock waves driven by coronal mass ejections in the inner heliosphere. Since solar energetic particle events increase radiation hazards in the near-Earth's space environment, the results from the project will also impact several NSF initiatives supporting the National Space Weather Program. The scientific outcome of this project will be disseminated via peer-reviewed journals, scientific meetings such as the AGU and SHINE workshops with active student participation, and space physics graduate-level curriculum at the UTSA. The project will also train one postdoctoral researcher and one half-time graduate student at the SwRI/UTSA. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.<br/><br/>The main objective of this SHINE project is to determine the relationships between the properties of locally accelerated ST ions observed in near-Earth's orbit and those of the concurrent in-situ interplanetary (IP) structures and provide observational constraints for the two main types of models. The project team will achieve this objective by answering the following three science questions: (1) what are the properties of potential IP sources of ST ions near 1 AU?; (2) what are the properties of locally accelerated ST ions associated with these IP structures?; and (3) what are the relationships between the properties of ST ions and those of the IP structures? In order to answer these questions, the project team will perform four tasks. The first task is to identify and eliminate the ST contributions from remote, discrete high-energy particle events. The second task is to identify and determine the properties of quiet-times and of IP structures such as compressions, rarefactions, CIRs, ICMEs, and IP shocks using ACE, Wind, and STEREO. The third task is to identify and determine the properties of ST ions associated with the above IP structures. The fourth task is to quantify the relationships and establish definitive links between properties of ST ions and IP structures and provide observational constraints for existing ST ion acceleration models.
