Return to "The Structure of the Magnetosphere" by
C. T. Russell.
"Magnetic Field Rotation Through the Magnetopause: ISEE 1 and 2
Observations:"
This is a brief summary of "Magnetic Field Rotation Through the Magnetopause:
ISEE 1 and 2 Observations:"
by J. Berchem and
C. T. Russell.
This paper was one of the references in C. T. Russell's "The
Structure of the Magnetopause," which I am attempting to
summarize.
The variability of the magnetopause prevents an immediate analysis of
the polarization (magnetic field angle) of the magnetopause. The sense of
the rotation through magnetopause crossings by the
ISEE
satellites can be compared with theoretical predictions for rotational
discontinuities. However, most of the crossings (about 61%) did not exhibit a
structure which had the coherence to be compared and analyzed, and very
few (a few percent) of
the crossings which did provide clear data actually agreed with
the Lee and Kan[1982] model for a rotational discontinuity.
Very few (so few that statistically it could be a coincidence) of the
crossings observed rotations which would confirm the electron whistler
polarization given by the first-order orbit theory of rotational
discontinuities. The authors conclude that the rotation of the magnetic
field depends more on the relative polarizations of the magnetosheath
and magnetospheric field than on the prescribed jump conditions.
Although the theory probably was too simplified for this analysis,
it illustrates the effect of undertaking analysis with the intent of
proving something. Berchem and Russell selected the events based on
magnetic field signatures, and not on jump conditions, which may have
affected the outcome of their results. Had they chosen to analyze the
events which appeared to be likely candidates for rotational
discontinuities, they probably would have had more evidence supporting
the theory.
"Evidence for Magnetic Field Reconnection at the
Earth's Magnetopause" by Sonnerup et al., [1981] uses
correlated data sets and provides more evidence for rotational
discontinuities.
Return to "The Structure of the Magnetosphere" by
C. T. Russell.