On Inferring Reformation of the Quasi-Perpendicular Bow Shock by Multi-Spacecraft Data

Details On Inferring Reformation of the Quasi-Perpendicular Bow Shock by Multi-Spacecraft Data On Inferring Reformation of the Quasi-Perpendicular Bow Shock by Multi-Spacecraft Data

Dec 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009agufmsh31a1456s&link_type=abstract

American Geophysical Union, Fall Meeting 2009, abstract #SH31A-1456

Physics

Plasma Physics

[2154] Interplanetary Physics / Planetary Bow Shocks, [2753] Magnetospheric Physics / Numerical Modeling, [7829] Space Plasma Physics / Kinetic Waves And Instabilities, [7851] Space Plasma Physics / Shock Waves

Scientific paper

Based on Cluster magnetic field and particle data obtained during a quasi-perpendicular bow shock crossing on 24 January 2001 Lobzin et al. (GRL 34, 2007) have concluded that the shock is nonstationary and reforming on the time scale of the ion gyroperiod. The argument for shock reformation is mainly based on the different magnetic field profiles observed by different spacecraft when traversing the bow shock. We have performed one-dimensional full-particle simulations for parameters appropriate to the 24 January 2001 shock crossing with the physical ion to electron mass ratio (it should be noted that the actual ion beta in the solar wind is ~ 0.6 as compared to 2.0 given by Lobzin et al.). The simulation exhibits large amplitude small wavelength waves in the foot, ramp, and overshoot simultaneously with vortices in the ion phase space of the incoming ions indicating the excitation of the modified two stream instability between incoming ions and electrons. These vortices lead to nonstationarity on a considerably smaller time scale than the ion gyroperiod. We have flown two closely spaced artificial satellite from upstream through the foot and ramp to downstream and have recorded the magnetic field profile during shock traversal. Due to the slight inherent motion of the ramp the two spacecraft measure, after low-pass filtering the data, different magnetic profiles. This is very similar to what has been observed after filtering the data obtained from the actual bow shock crossing. It is concluded that during the 24 January 2001 crossing the bow shock is actually not reforming, but nonstationary on a time scale much smaller than the ion gyroperiod. This nonstationarity can not be seen in the filtered spacecraft data. The difference of the large scale magnetic field profiles measured aboard different Cluster spacecraft is probably due to a combination of small back and forth motion of the bow shock and small temporal changes of the shock structure, but is not necessarily prove for shock reformation.

Affiliated with

Also associated with

No associations

Rating

On Inferring Reformation of the Quasi-Perpendicular Bow Shock by Multi-Spacecraft Data 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 On Inferring Reformation of the Quasi-Perpendicular Bow Shock by Multi-Spacecraft Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On Inferring Reformation of the Quasi-Perpendicular Bow Shock by Multi-Spacecraft Data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1783593