Turbulence in the Outer Heliosphere

• Published in: Space science reviews 2022-09, Vol.218 (6), Article 50
• Main Authors: Fraternale, Federico, Adhikari, Laxman, Fichtner, Horst, Kim, Tae K., Kleimann, Jens, Oughton, Sean, Pogorelov, Nikolai V., Roytershteyn, Vadim, Smith, Charles W., Usmanov, Arcadi V., Zank, Gary P., Zhao, Lingling
• Format: Article
• Language: English
• Subjects: Aerospace Technology and Astronautics; Astrophysics and Astroparticles; Charge exchange; Cosmic rays; Energetic neutral atoms; Heliosphere; Interstellar medium; Local interstellar medium; Magnetic fields; Neutral atoms; New Horizons mission; Physics; Physics and Astronomy; Planetology; Solar wind; Solar wind turbulence; Space Exploration and Astronautics; Space missions; Space Sciences (including Extraterrestrial Physics; Spacecraft; Turbulence; Turbulent flow
• ISSN: 0038-6308; 1572-9672
• DOI: 10.1007/s11214-022-00914-2

The solar wind (SW) and local interstellar medium (LISM) are turbulent media. Their interaction is governed by complex physical processes and creates heliospheric regions with significantly different properties in terms of particle populations, bulk flow and turbulence. Our knowledge of the solar wind turbulence nature and dynamics mostly relies on near-Earth and near-Sun observations, and has been increasingly improving in recent years due to the availability of a wealth of space missions, including multi-spacecraft missions. In contrast, the properties of turbulence in the outer heliosphere are still not completely understood. In situ observations by Voyager and New Horizons , and remote neutral atom measurements by IBEX strongly suggest that turbulence is one of the critical processes acting at the heliospheric interface. It is intimately connected to charge exchange processes responsible for the production of suprathermal ions and energetic neutral atoms. This paper reviews the observational evidence of turbulence in the distant SW and in the LISM, advances in modeling efforts, and open challenges.