# Modeling Shocks Detected by Voyager 1 in the Local Interstellar Medium

## TL;DR

This study models magnetic field shocks detected by Voyager 1 in the local interstellar medium, revealing the influence of solar transients and ICMEs on interstellar magnetic fluctuations beyond the heliopause.

## Contribution

It introduces a data-driven, multi-fluid model incorporating time-dependent solar wind effects to simulate interstellar magnetic field shocks observed by Voyager 1.

## Key findings

- Model reproduces large-scale magnetic fluctuations observed by Voyager 1.
- Predicted shocks at Voyager 1 around 2017.4 and 2019.5.
- ICMEs significantly influence shock propagation into the interstellar medium.

## Abstract

The magnetometer (MAG) on Voyager 1 (V1) has been sampling the interstellar magnetic field (ISMF) since August 2012. The V1 MAG observations have shown draped ISMF in the very local interstellar medium disturbed occasionally by significant enhancements in magnetic field strength. Using a three-dimensional, data driven, multi-fluid model, we investigated these magnetic field enhancements beyond the heliopause that are supposedly associated with solar transients. To introduce time-dependent effects at the inner boundary at 1 astronomical unit, we used daily averages of the solar wind parameters from the OMNI data set. The model ISMF strength, direction, and proton number density are compared with V1 data beyond the heliopause. The model reproduced the large-scale fluctuations between 2012.652 and 2016.652, including major events around 2012.9 and 2014.6. The model also predicts shocks arriving at V1 around 2017.395 and 2019.502. Another model driven by OMNI data with interplanetary coronal mass ejections (ICMEs) removed at the inner boundary suggests that ICMEs may play a significant role in the propagation of shocks into the interstellar medium.