Nonlinear ion-acoustic waves, ion holes, and electron holes have been observed on the Parker Solar Probe at a heliocentric distance of 35 solar radii. These time domain structures contain millisecond duration electric field spikes of several mV m−1. They are observed inside or at boundaries of switchbacks in the background magnetic field. Their presence in switchbacks indicates that both electron- and ion-streaming electrostatic instabilities occur there to thermalize electron and ion beams.
Bibliographical noteFunding Information:
This work was supported by NASA contract NASA-G-80NSSC19K1063. The authors acknowledge the extraordinary contributions of the Parker Solar Probe spacecraft engineering team at the Applied Physics Laboratory at Johns Hopkins University. Our sincere thanks to S. Bale, P. Harvey, K. Goetz, and M. Pulupa for managing the FIELDS science, the spacecraft commanding, and data processing. The work of I.V. was supported by NASA grant 80NSSC18K0646 and National Science Foundation grant No. 2026680. The data used in this paper are publicly available at http://fields.ssl.berkeley.edu/data.
© 2021. The Author(s). Published by the American Astronomical Society.