Multi-spacecraft observations of shocklets at an interplanetary shock

Abstract

Interplanetary (IP) shocks are fundamental building blocks of the heliosphere, and the possibility to observe them \emph{in-situ} is crucial to address important aspects of energy conversion for a variety of astrophysical systems. Steepened waves known as shocklets are known to be important structures of planetary bow shocks, but they are very rarely observed related to IP shocks. We present here the first multi-spacecraft observations of shocklets observed by upstream of an unusually strong IP shock observed on November 3rd 2021 by several spacecraft at L1 and near-Earth solar wind. The same shock was detected also by radially aligned Solar Orbiter at 0.8 AU from the Sun, but no shocklets were identified from its data, introducing the possibility to study the environment in which shocklets developed. The Wind spacecraft has been used to characterise the shocklets, associated with pre-conditioning of the shock upstream by decelerating incoming plasma in the shock normal direction. Finally, using the Wind observations together with ACE and DSCOVR spacecraft at L1, as well as THEMIS B and THEMIS C in the near-Earth solar wind, the portion of interplanetary space filled with shocklets is addressed, and a lower limit for its extent is estimated to be of about 110 $R_E$ in the shock normal direction and 25 $R_E$ in the directions transverse to the shock normal. Using multiple spacecraft also reveals that for this strong IP shock, shocklets are observed for a large range of local obliquity estimates (9-64 degrees).

Submitted to Monthly Notices of the Royal Astronomical Society

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Cited by in corpus (7)

• Three-dimensional modelling of the shock-turbulence interaction
• Interplanetary Shock Data Base
• Backstreaming ions at a high Mach number interplanetary shock: Solar Orbiter measurements during the nominal mission phase
• The solar cycle 25 multi-spacecraft solar energetic particle event catalog of the SERPENTINE project
• Interpretation of flat energy spectra upstream of fast interplanetary shocks
• Compressive Structures in the Foreshock of Collisionless Shocks
• Numerical investigation of particle acceleration at interplanetary shocks: diffusive and superdiffusive scenarios