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Title: Electrostatic Solitary Waves in the Earth's Bow Shock: Nature, Properties, Lifetimes, and Origin
Abstract

We present a statistical analysis of >2,100 bipolar electrostatic solitary waves (ESWs) collected from 10 quasi‐perpendicular Earth's bow shock crossings by Magnetospheric Multiscale spacecraft. We developed and implemented a correction procedure for reconstruction of actual electric fields, velocities, and other properties of ESW, whose spatial scales are typically comparable with or smaller than spatial distance between voltage‐sensitive probes. We found that more than 95% of the ESW are of negative polarity with amplitudes typically below a few Volts and 0.1Te(5–30 V or 0.1–0.3Tefor a few percent of ESW), spatial scales of 10–100 m orλD–10λD, and velocities from a few tens to a few hundred km/s that is on the order of local ion‐acoustic speed. The spatial scales of ESW are correlated with local Debye lengthλD. The ESW have electric fields generally oblique to magnetic field and they propagate highly oblique to shock normalN; more than 80% of ESW propagate within 30° of the shock planeLM. In the shock plane, ESW typically propagates within a few tens of degrees of local magnetic field projectionBLMand preferentially opposite toN × BLM. We argue that the ESW of negative polarity are ion holes produced by ion‐ion streaming instabilities. We estimate ion hole lifetimes to be 10–100 ms, or 1–10 km in terms of traveling distance. The revealed statistical properties will be useful for quantitative studies of electron thermalization in the Earth's bow shock.

 
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Award ID(s):
2026680 1902684
NSF-PAR ID:
10369678
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
DOI PREFIX: 10.1029
Date Published:
Journal Name:
Journal of Geophysical Research: Space Physics
Volume:
126
Issue:
7
ISSN:
2169-9380
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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