Interplanetary fast shocks and associated drivers observed through the 23rd solar minimum by Wind over its first 2.5 years

Physics – Plasma Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

44

Interplanetary Physics: Interplanetary Shocks, Interplanetary Physics: Solar Cycle Variations, Space Plasma Physics: Shock Waves

Scientific paper

A list of the interplanetary shocks observed by Wind from its launch (in Nov 1994) to May 1997 is presented. The magnetohydrodynamic nature of the shocks is investigated, and the associated shock parameters and their uncertainties are accurately computed using two techniques. These are: 1) a combination of the ``preaveraged'' magnetic-coplanarity, velocity-coplanarity, and the Abraham-Schrauner-mixed methods, and 2) the Viñas and Scudder [1986] technique for solving the nonlinear least squares Rankine-Hugoniot equations. Within acceptable limits these two techniques generally gave the same results, with some exceptions. The reasons for the exceptions are discussed. The mean strength and rate of occurrence of the shocks appear to correlate with the solar cycle. Both showed a decrease in 1996 coincident with the time of the lowest ultraviolet solar radiance, indicative of solar minimum and the beginning of solar cycle 23. Eighteen shocks appeared to be associated with corotating interaction regions (CIRs). The shock normal distribution showed a mean direction peaking in the ecliptic plane and with a longitude of ~200° (GSE coordinates). Another 16 shocks were determined to be driven by solar transients, including magnetic clouds. These had a broader distribution of normal directions than those of the CIR cases with a mean direction close to the Sun-Earth line. Eight shocks of unknown origin had normal orientations far off the ecliptic plane. No shock propagated with longitude φn>=220+/-10°, i.e. against the average Parker spiral direction. Examination of the obliquity angle θBn (i.e., between the shock normal and the upstream interplanetary magnetic field) for the full set of shocks revealed that about 58% were quasi-perpendicular, and about 32% of the shocks oblique, and the rest quasi-parallel. Small uncertainty in the estimated angle θBn was obtained for about 10 shocks with magnetosonic Mach numbers between 1 and 2.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Interplanetary fast shocks and associated drivers observed through the 23rd solar minimum by Wind over its first 2.5 years does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Interplanetary fast shocks and associated drivers observed through the 23rd solar minimum by Wind over its first 2.5 years, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interplanetary fast shocks and associated drivers observed through the 23rd solar minimum by Wind over its first 2.5 years will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1050966

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.