Coronal mass ejections and magnetic flux buildup in the heliosphere

Owens, M. J. ORCID: https://orcid.org/0000-0003-2061-2453 and Crooker, N. U. (2006) Coronal mass ejections and magnetic flux buildup in the heliosphere. Journal of Geophysical Research, 111 (A10). A10104. ISSN 0148-0227 doi: 10.1029/2006JA011641

Abstract/Summary

To test for magnetic flux buildup in the heliosphere from coronal mass ejections (CMEs), we simulate heliospheric flux as a constant background open flux with a time-varying interplanetary CME (ICME) contribution. As flux carried by ejecta can only contribute to the heliospheric flux budget while it remains closed, the ICME flux opening rate is an important factor. Two separate forms for the ICME flux opening rate are considered: (1) constant and (2) exponentially decaying with time. Coronagraph observations are used to determine the CME occurrence rates, while in situ observations are used to estimate the magnetic flux content of a typical ICME. Both static equilibrium and dynamic simulations, using the constant and exponential ICME flux opening models, require flux opening timescales of ∼50 days in order to match the observed doubling in the magnetic field intensity at 1 AU over the solar cycle. Such timescales are equivalent to a change in the ICME closed flux of only ∼7–12% between 1 and 5 AU, consistent with CSE signatures; no flux buildup results. The dynamic simulation yields a solar cycle flux variation with high variability that matches the overall variability of the observed magnetic field intensity remarkably well, including the double peak forming the Gnevyshev gap.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/5831
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items
Uncontrolled Keywords	CMEs, heliospheric flux, interplanetary magnetic field.
Publisher	American Geophysical Union
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