@article{discovery10196979,
            note = {Copyright {\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.},
          number = {16},
         journal = {Geophysical Research Letters},
            year = {2024},
           title = {Ion-Acoustic Waves Associated With Interplanetary Shocks},
       publisher = {AMER GEOPHYSICAL UNION},
           month = {August},
          volume = {51},
            issn = {0094-8276},
          author = {Boldu, JJ and Graham, DB and Morooka, M and Andre, M and Khotyaintsev, Yu V and Dimmock, A and Pisa, D and Soucek, J and Maksimovic, M and Louarn, P and Fedorov, A and Nicolaou, G and Owen, C},
             url = {http://dx.doi.org/10.1029/2024gl109956},
        abstract = {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.},
        keywords = {Collisionless shock; plasma waves; instabilities}
}