Magnetic field fluctuations observed in the heliosheath by Voyager 1 at 114 ± 2 AU During 2010

摘要

[1]The radial component of the flow speed VR in the heliosheath was decreasing between 2009.0(108.5 AU)and 2010.3, at which time it reached the "stagnation region" where VR ≈ 0 km/s from 2010.3 to at least to 2011.0(115.7 AU). The fluctuations of the hour averages of the magnetic field B observed by Voyager 1(V1)each day throughout 2010 were primarily compressive(longitudinal)fluctuations, along the T(average B)direction in HG coordinates. The yearly average of the daily standard deviations(SD)of the compressive component of B was 〈SD _c〉 = 〈SD(BT)〉 ≈ 〈SD(B)〉 ≈ 0.015 nT. The corresponding standard deviations of the transverse components 〈SD _t〉 = SD(BR)> ≈ 〈SD(BN)〉 ≈ 0.006 nT. During 2010, 〈SD _c〉/ 〈SD _t〉 > 2.6 and 〈SD _c〉/〈B〉 = 0.15. The counting rate of cosmic rays >70 MeV/nuc tends to increase with increasing B and SD _c, contrary to expectations.