TY  - JOUR
KW  - Collisionless shock; plasma waves; instabilities
N1  - Copyright © 2024. The Author(s). Geophysical Research Letters published by Wiley Periodicals LLC on behalf of American Geophysical Union.
This is an open access article under the terms of the Creative Commons Attribution License, https://creativecommons.org/licenses/by/4.0/, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
EP  - 10
IS  - 16
AV  - public
SN  - 0094-8276
TI  - Ion-Acoustic Waves Associated With Interplanetary Shocks
JF  - Geophysical Research Letters
PB  - AMER GEOPHYSICAL UNION
A1  - Boldu, JJ
A1  - Graham, DB
A1  - Morooka, M
A1  - Andre, M
A1  - Khotyaintsev, Yu V
A1  - Dimmock, A
A1  - Pisa, D
A1  - Soucek, J
A1  - Maksimovic, M
A1  - Louarn, P
A1  - Fedorov, A
A1  - Nicolaou, G
A1  - Owen, C
VL  - 51
UR  - http://dx.doi.org/10.1029/2024gl109956
ID  - discovery10196979
N2  - Ion-acoustic waves (IAWs) commonly occur near interplanetary (IP) shocks. These waves are important because of their potential role in the dissipation required for collisionless shocks to exist. We study IAW occurrence statistically at different heliocentric distances using Solar Orbiter to identify the processes responsible for IAW generation near IP shocks. We show that close to IP shocks the occurrence rate of IAW increases and peaks at the ramp. In the upstream region, the IAW activity is highly variable among different shocks and increases with decreasing distance from the Sun. We show that the observed currents near IP shocks are insufficient to reach the threshold for the current-driven instability. We argue that two-stream proton distributions and suprathermal electrons are likely sources of the waves.
Y1  - 2024/08/28/
ER  -