Hydrodynamic Modeling of Heating Processes in Solar Flares

dc.contributor.advisorBradshaw, Stephen Jen_US
dc.contributor.committeeMemberAlexander, Daviden_US
dc.contributor.committeeMemberWarburton, Timen_US
dc.creatorReep, Jeffreyen_US
dc.date.accessioned2016-01-25T16:59:19Zen_US
dc.date.available2016-01-25T16:59:19Zen_US
dc.date.created2014-12en_US
dc.date.issued2014-10-09en_US
dc.date.submittedDecember 2014en_US
dc.date.updated2016-01-25T16:59:19Zen_US
dc.description.abstractThis thesis examines the heating of the solar atmosphere due to energy release in solar flares. A one-dimensional hydrodynamic model, which solves the equations of conservation of mass, momentum, and energy along a magnetic flux tube, is described in detail and employed to study the dynamic response of the solar atmosphere to large amounts of energy release from the magnetic field. A brief introduction to the solar atmosphere and solar flares, from both observational and theoretical perspectives, is given. Then, the hydrodynamic model is described, along with derivations of energy deposition due to a beam of highly energetic electrons colliding with the ambient atmosphere (and their implementation in the model is explained). Using this model of heating along with RHESSI-derived parameters of observed flares, the sensitivity of the GOES flare classification to the parameters of the electron beam (the non-thermal energy, the power-law index of the electron distribution, and the low-energy cut-off) are examined, and clear correlations are determined. Next, the response of the atmosphere to heating due to isoenergetic beams of electrons are studied, to elucidate the importance of electrons at different energy. It is found that at high total energy fluxes, the energy of individual electrons are unimportant, but that at lower fluxes, lower energy electrons are significantly more efficient at heating the atmosphere and driving chromospheric evaporation than high energy electrons. It is also found that the threshold for explosive evaporation is strongly dependent on the cut-off energy, as well as the beam flux. A case study of a well-observed flare is performed. The flare, a C-class flare that occurred on 28 November 2002, was modeled for various cases of heating due to a beam of electrons, in situ coronal heating, and a hybrid model that combines both forms of heating. It is found that the observation of X-ray source heights seen with RHESSI are most consistent with a hybrid model. The results indicate that the energy must be partitioned between thermal and kinetic energy, and the implications are discussed. This work is then summarized, and future avenues of research are discussed. Improvements that can be made to the model, the forward modeling of emission, and comparisons to observations are discussed.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationReep, Jeffrey. "Hydrodynamic Modeling of Heating Processes in Solar Flares." (2014) Diss., Rice University. <a href="https://hdl.handle.net/1911/88108">https://hdl.handle.net/1911/88108</a>.en_US
dc.identifier.urihttps://hdl.handle.net/1911/88108en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectSolar Physicsen_US
dc.subjectSolar Flaresen_US
dc.subjectSunen_US
dc.subjectSolar Atmosphereen_US
dc.subjectCoronaen_US
dc.subjectHydrodynamic Modelingen_US
dc.titleHydrodynamic Modeling of Heating Processes in Solar Flaresen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentPhysics and Astronomyen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US
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