# Radio Observational Constraints on Turbulent Astrophysical Plasmas

## TL;DR

This paper discusses how ground-based radio observations, especially with the upcoming ngVLA, can significantly advance the study of turbulence in astrophysical plasmas like the solar wind and interstellar medium.

## Contribution

It highlights the potential of radio propagation phenomena and the ngVLA to enhance understanding of plasma turbulence beyond in situ measurements.

## Key findings

- Radio observations can map plasma properties of the solar corona and interstellar medium.
- Radio phenomena like scintillations and Faraday rotation provide insights into turbulence.
- Next Generation Very Large Array will enable comprehensive turbulence studies.

## Abstract

Remarkable progress has been made in understanding turbulent astrophysical plasmas in past decades including, notably, the solar wind and the interstellar medium. In the case of the solar wind, much of this progress has relied on in situ measurements from space-borne instruments. However, ground-based radio observations also have played a significant role and have the potential to play an even bigger role. In particular, using distant background sources (quasars, pulsars, satellite beacons) to transilluminate the foreground corona and solar wind, a variety of radio propagation phenomena can be used to map plasma properties of the solar corona and heliosphere, as well as the warm interstellar medium. These include angular broadening, interplanetary and interstellar scintillations, and differential Faraday rotation. These observations are highly complementary to in situ observations of the solar wind, and could be a mainstay of investigations into turbulence of the ISM. We point out that the Next Generation Very Large Array (ngVLA) fulfills all the requirements necessary to exploit radio observations of astrophysical turbulence fully.