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Title: Magnetic flux conservation in an imploding plasma

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Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
SC0016258; AR0000568
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review E
Additional Journal Information:
Journal Volume: 97; Journal Issue: 1; Related Information: CHORUS Timestamp: 2018-01-08 10:20:24; Journal ID: ISSN 2470-0045
American Physical Society
Country of Publication:
United States

Citation Formats

García-Rubio, F., Sanz, J., and Betti, R.. Magnetic flux conservation in an imploding plasma. United States: N. p., 2018. Web. doi:10.1103/PhysRevE.97.011201.
García-Rubio, F., Sanz, J., & Betti, R.. Magnetic flux conservation in an imploding plasma. United States. doi:10.1103/PhysRevE.97.011201.
García-Rubio, F., Sanz, J., and Betti, R.. 2018. "Magnetic flux conservation in an imploding plasma". United States. doi:10.1103/PhysRevE.97.011201.
title = {Magnetic flux conservation in an imploding plasma},
author = {García-Rubio, F. and Sanz, J. and Betti, R.},
abstractNote = {},
doi = {10.1103/PhysRevE.97.011201},
journal = {Physical Review E},
number = 1,
volume = 97,
place = {United States},
year = 2018,
month = 1

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on January 8, 2019
Publisher's Accepted Manuscript

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  • We estimate axial lengths of helical parts in magnetic clouds (MCs) at 1 AU from the magnetic flux (magnetic helicity) conservation between solar active regions (ARs) and MCs with the event list of Leamon et al. Namely, considering poloidal magnetic flux (PHI{sub P}) conservation between MCs and ARs, we estimated L{sub h} in MCs, where L{sub h} is the axial length of an MC where poloidal magnetic flux and magnetic twist exist. It is found that L{sub h} is 0.01-1.25 AU in the MCs. If the cylinder flux rope picture is assumed, this result leads to a possible new picturemore » of the cylinder model whose helical structure (namely, poloidal magnetic flux) localizes in a part of a MC.« less
  • In the heliosheath (HS), Voyager 2 has observed a flow with constant radial velocity and magnetic flux conservation. Voyager 1, however, has observed a decrease in the flow’s radial velocity and an order of magnitude decrease in magnetic flux. We investigate the role of the 11 yr solar cycle variation of the magnetic field strength on the magnetic flux within the HS using a global 3D magnetohydrodynamic model of the heliosphere. We use time and latitude-dependent solar wind velocity and density inferred from Solar and Heliospheric Observatory/SWAN and interplanetary scintillations data and implemented solar cycle variations of the magnetic fieldmore » derived from 27 day averages of the field magnitude average of the magnetic field at 1 AU from the OMNI database. With the inclusion of the solar cycle time-dependent magnetic field intensity, the model matches the observed intensity of the magnetic field in the HS along both Voyager 1 and 2. This is a significant improvement from the same model without magnetic field solar cycle variations, which was over a factor of two larger. The model accurately predicts the radial velocity observed by Voyager 2; however, the model predicts a flow speed ∼100 km s{sup −1} larger than that derived from LECP measurements at Voyager 1. In the model, magnetic flux is conserved along both Voyager trajectories, contrary to observations. This implies that the solar cycle variations in solar wind magnetic field observed at 1 AU does not cause the order of magnitude decrease in magnetic flux observed in the Voyager 1 data.« less
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  • Voyager 1(V1) and Voyager 2(V2) have observed heliosheath plasma since 2005 December and 2007 August, respectively. The observed speed profiles are very different at the two spacecrafts. Speeds at V1 decreased to zero in 2010 while the average speed at V2 is a constant 150 km s{sup -1} with the direction rotating tailward. The magnetic flux is expected to be constant in these heliosheath flows. We show that the flux is constant at V2 but decreases by an order of magnitude at V1, even after accounting for divergence of the flows and changes in the solar field. If reconnection weremore » responsible for this decrease, the magnetic field would lose 70% of its free energy to reconnection and the energy density released would be 0.6 eV cm{sup -3}.« less