Imperial College London

Dr Jonathan P. Eastwood

Faculty of Natural SciencesDepartment of Physics

Senior Lecturer



+44 (0)20 7594 8101jonathan.eastwood Website




6M63Blackett LaboratorySouth Kensington Campus






BibTex format

author = {Archer, MO and Horbury, TS and Eastwood, JP},
doi = {10.1029/2011JA017468},
journal = {Journal of Geophyical Research},
title = {Magnetosheath pressure pulses: Generation downstream of the bow shock from solar wind discontinuities},
url = {},
volume = {117},
year = {2012}

RIS format (EndNote, RefMan)

AB - We present multipoint Time History of Events and Macroscale Interactions duringSubstorms (THEMIS) observations of transient dynamic pressure pulses in themagnetosheath 3–10 times the background in amplitude, due to enhancements in both theion density and velocity. Their spatial dimensions are of the order of 1 RE parallel tothe flow and 0.2–0.5 RE perpendicular to it, inferred from the difference in theamplitudes observed by the different spacecraft. For the first time, simultaneousobservations of the solar wind and foreshock are also shown, proving no similar dynamicpressure enhancements exist upstream of the bow shock and that the majority of pulsesare downstream of the quasi-parallel shock. By considering previously suggestedmechanisms for their generation, we show that the pressure pulses cannot be caused byreconnection, hot flow anomalies, or short, large-amplitude magnetic structures andthat at least some of the pressure pulses appear to be consistent with previoussimulations of solar wind discontinuities interacting with the bow shock. Thesesimulations predict large-amplitude pulses when the local geometry of the shock changesfrom quasi-perpendicular to quasi-parallel, while the opposite case should also producenotable pulses but typically of lower amplitude. Therefore, in a given region of themagnetosheath, some of the discontinuities in the solar wind should generate pressurepulses, whereas others are expected not to. There is also evidence that the pulses canimpinge upon the magnetopause, causing its motion.
AU - Archer,MO
AU - Horbury,TS
AU - Eastwood,JP
DO - 10.1029/2011JA017468
PY - 2012///
SN - 0148-0227
TI - Magnetosheath pressure pulses: Generation downstream of the bow shock from solar wind discontinuities
T2 - Journal of Geophyical Research
UR -
UR -
VL - 117
ER -