Topology and convection of a northward interplanetary magnetic field reconnection event

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dc.contributor.advisorReiff, Patricia H.en_US
dc.creatorWendel, Deirdre E.en_US
dc.date.accessioned2018-12-03T18:32:37Zen_US
dc.date.available2018-12-03T18:32:37Zen_US
dc.date.issued2009en_US
dc.description.abstractFrom observations and global MHD simulations, we deduce the local and global magnetic topology and current structure of a northward IMF reconnection event in the dayside magnetopause. The ESA four-satellite Cluster suite crossed the magnetopause at a location mapping along field lines to an ionospheric H-alpha emission observed by the IMAGE spacecraft. Therefore, we seek reconnection signatures in the Cluster data. From the four-point Cluster observations, we develop a superposed epoch method to find the instantaneous x-line, its associated current sheet, and the nature of the reconnecting particle flows. This method is unique in that it removes the motion of the hyperbolic structure and the magnetopause relative to the spacecraft. We detect singular field line reconnection—planar hyperbolic reconnecting fields superposed on an out-of-plane field. We also detect the non-ideal electric field that is required to certify reconnection at locations where the magnetic field does not vanish, and estimate a reconnection electric field of -4 mV/m. The current sheet appears bifurcated, embedding a 30 km current sheet of opposite polarity within a broader current sheet about 130 km thick. Using a resistive MHD simulation and ionospheric satellite data, we examine the same event at global length scales. This gives a 3D picture of where reconnection occurs on the magnetopause for northward IMF with B x and B y components and a tilted dipole field. It also demonstrates that northward IMF 3D reconnection couples the reconnection electric field and field-aligned currents to the ionosphere, driving sunward convection in a manner that agrees with satellite measurements of sunward flows. We find singular field line reconnection of the IMF with both open and closed field lines near nulls in both hemispheres. The reconnection in turn produces both open and closed field lines. We discuss for the first time how line-tying in the ionosphere and draping of open and IMF field lines produce a torsion of the reconnecting singular magnetic field lines within the magnetopause. The simulation and data show that magnetopause reconnection topology is three-dimensional in a way that challenges accepted models of neutral lines and x-lines with guide fields.en_US
dc.format.extent226 ppen_US
dc.identifier.callnoTHESIS SP. SCI. 2009 WENDELen_US
dc.identifier.citationWendel, Deirdre E.. "Topology and convection of a northward interplanetary magnetic field reconnection event." (2009) Diss., Rice University. <a href="https://hdl.handle.net/1911/103685">https://hdl.handle.net/1911/103685</a>.en_US
dc.identifier.digital304988467en_US
dc.identifier.urihttps://hdl.handle.net/1911/103685en_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.subjectAstronomyen_US
dc.subjectPlasma physicsen_US
dc.subjectPure sciencesen_US
dc.subjectMagnetic reconnectionen_US
dc.subjectMagnetopauseen_US
dc.subjectMagnetospheric convectionen_US
dc.titleTopology and convection of a northward interplanetary magnetic field reconnection eventen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentSpace Scienceen_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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