Return to "The Structure of the Magnetosphere" by
C. T. Russell.
"Plasma Acceleration at the Earth's Magnetopause: Evidence for
Reconnection:"
This is a brief summary of
"Plasma Acceleration at the Earth's Magnetopause: Evidence for
Reconnection"
by G. Paschmann, B.U.O. Sonnerup, I. Papamastorakis, N. Schopke, G.
Haerendel, S. J. Bame, J. R. Asbridge, J. T. Gosling,
C. T. Russell
and R. C. Elphic.
This paper was one of the references in C. T. Russell's "The
Structure of the Magnetopause," which I am attempting to
summarize.
Several samples obtained from crossings by
ISEE
satellites show evidence
for a rotational discontinuity. The data is compared with a model
consisting of a standing Alfven wave at the magnetopause, resulting
in a slingshot effect after reconnection. The flow speeds in the
magnetopause were as high as 450 km/sec, and were compared with
magnetosheath speeds of 50 - 100 km/sec to obtain predictions for a
rotational discontinuity. The magnetic fields, densities, and flows
appeared to indicate that the observation fit their predictions within
the bounds of instrumental accuracy, although these bounds occasionally
approached the predicted values in magnitude.
Paschmann et al. noted that the overall magnetopause thickness was
approximately 900 km with a magnetopause velocity of 10 km/sec.
Although they used discrete jump conditions to
analyze the data, they also used a relation to represent average
magnetosheath conditions, by assuming a linear slope between the transverse
magnetic field and the density times the transverse velocity. Most of the
data agreed with the predicted value for the slope.
These observations comprise the first actual evidence for reconnection,
beyond theoretical prediction. Though I was only ten at the time, this
must have been an exciting piece of research.
"Magnetic Field Rotation Through the Magnetopause:
ISEE 1 and 2 Observations" by J. Berchem and C. T. Russell
and "Evidence for Magnetic Field Reconnection
at the Earth's Magnetopause" by Sonnerup et al. [1981]
provide better statistics on this subject.
Return to "The Structure of the Magnetosphere" by
C. T. Russell.