The temporal and latitudinal dependences of turbulence driven by pickup ions in the outer heliosphere

Bibliographic Details
Title: The temporal and latitudinal dependences of turbulence driven by pickup ions in the outer heliosphere
Authors: Bingbing Wang, Lingling Zhao, Paria Abouhamzeh, Gary P. Zank, Laxman Adhikari
Source: Frontiers in Astronomy and Space Sciences, Vol 10 (2023)
Publisher Information: Frontiers Media S.A., 2023.
Publication Year: 2023
Collection: LCC:Astronomy
LCC:Geophysics. Cosmic physics
Subject Terms: magnetohydrodynamic turbulence, heliosphere, solar wind, waves and instabilities, pickup ions, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
More Details: The distribution of turbulence in the heliosphere remains a mystery, due to the complexity in not only modeling the turbulence transport equations but also identifying the drivers of turbulence that vary with time and spatial location. Beyond the ionization cavity (a few astronomical units (AU) from the Sun), the turbulence is driven predominantly by freshly created pickup ions (PUIs), in contrast to the driving by stream shear and compression. Understanding the source characteristics is necessary to refine turbulence transport models and interpret measurements of turbulence and solar wind temperature in the outer heliosphere. Using a recent latitude-dependent solar wind speed model and the ionization rate of neutral interstellar hydrogen (H), we investigate the temporal and spatial variation in the strength of low-frequency turbulence driven by PUIs from 1998 to 2020. We find that the driving rate is stronger during periods of high solar activity and at lower latitudes in the outer heliosphere. The driving rates for parallel and anti-parallel propagating (relative to the background magnetic field) slab turbulence have different spatial and latitude dependences. The calculated generation rate of turbulence by PUIs is an essential ingredient to investigate the latitude dependence of turbulence in the outer heliosphere, which is important to understand the heating of the distant solar wind and the modulation of cosmic rays.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2296-987X
Relation: https://www.frontiersin.org/articles/10.3389/fspas.2023.1298577/full; https://doaj.org/toc/2296-987X
DOI: 10.3389/fspas.2023.1298577
Access URL: https://doaj.org/article/ec63571516834b40aa56a558f84e9549
Accession Number: edsdoj.63571516834b40aa56a558f84e9549
Database: Directory of Open Access Journals
More Details
ISSN:2296987X
DOI:10.3389/fspas.2023.1298577
Published in:Frontiers in Astronomy and Space Sciences
Language:English