Transition from the Unipolar Region to the Sector Zone: Voyager 2, 2013 and 2014
- NASA Goddard Space Flight Center, Code 673, Greenbelt, MD 20771 (United States)
- Dept. of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)
We discuss magnetic field and plasma observations of the heliosheath made by Voyager 2 (V2) during 2013 and 2014 near solar maximum. A transition from a unipolar region to a sector zone was observed in the azimuthal angle λ between ∼2012.45 and 2013.82. The distribution of λ was strongly singly peaked at 270{sup ∘} in the unipolar region and double peaked in the sector zone. The δ-distribution was strongly peaked in the unipolar region and very broad in the sector zone. The distribution of daily averages of the magnetic field strength B was Gaussian in the unipolar region and lognormal in the sector zone. The correlation function of B was exponential with an e-folding time of ∼5 days in both regions. The distribution of hourly increments of B was a Tsallis distribution with nonextensivity parameter q = 1.7 ± 0.04 in the unipolar region and q = 1.44 ± 0.12 in the sector zone. The CR–B relationship qualitatively describes the 2013 observations, but not the 2014 observations. A 40 km s{sup −1} increase in the bulk speed associated with an increase in B near 2013.5 might have been produced by the merging of streams. A “D sheet” (a broad depression in B containing a current sheet moved past V2 from days 320 to 345, 2013. The R- and N-components of the plasma velocity changed across the current sheet.
- OSTI ID:
- 22872693
- Journal Information:
- Astrophysical Journal, Vol. 841, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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