CORRELATIONS OF PLASMA DENSITY AND MAGNETIC FIELD STRENGTH IN THE HELIOSHEATH

The crossing of the termination shock (TS) by Voyager 2 in 2007 at 84 AU allows a comparison of fluctuations in different heliosheath regions. The Letter concentrates on MHD waves that exhibit a significant correlation between the magnetic field strength and plasma density. The correlations between both quantities were computed on 2?hr time intervals in the frequency range of 1 × 10[superscript -4] to 4 × 10[superscript -3] Hz. We separate the data into two regions with different magnetic field behavior; the post-TS region with many crossings of the current sheet and the unipolar region where the magnetic field direction remains nearly constant. We find that typical correlation coefficients in these regions are about 0.55-0.65, larger than in Earth's magnetosheath. The largest correlations occur when the spectrum of magnetic field fluctuations is dominated by low frequencies.Grant Agency of the Czech Republic (Contract 205/09/0170)Grant Agency of the Czech Republic (Contract 205/07/0694)Grant Agency of the Czech Republic (Contract 202/08/H057)Czech Republic. Ministry of Education (Research Plan 0021620860)United States. National Aeronautics and Space Administration (Voyager Project)United States. National Aeronautics and Space Administration (Grant NNX08AC04G