# Predictions for the First Parker Solar Probe Encounter

## TL;DR

This paper uses the AWSoM model to predict plasma conditions during the first Parker Solar Probe encounter, focusing on coronal heating, wave turbulence, and plasma stability near the heliospheric current sheet.

## Contribution

It provides the first detailed predictions of plasma states and wave interactions during PSP's initial perihelion, integrating Alfvén wave turbulence and heating theories.

## Key findings

- PSP was near the heliospheric current sheet during the encounter.
- Predicted plasma shows dominant proton parallel temperature.
- Plasma conditions suggest firehose instability near the HCS.

## Abstract

We examine Alfv\'en Wave Solar atmosphere Model (AWSoM) predictions of the first Parker Solar Probe (PSP) encounter. We focus on the 12-day closest approach centered on the 1st perihelion. AWSoM (van der Holst et al., 2014) allows us to interpret the PSP data in the context of coronal heating via Alfv\'en wave turbulence. The coronal heating and acceleration is addressed via outward-propagating low-frequency Alfv\'en waves that are partially reflected by Alfv\'en speed gradients. The nonlinear interaction of these counter-propagating waves results in a turbulent energy cascade. To apportion the wave dissipation to the electron and anisotropic proton temperatures, we employ the results of the theories of linear wave damping and nonlinear stochastic heating as described by Chandran et al. (2011). We find that during the first encounter, PSP was in close proximity to the heliospheric current sheet (HCS) and in the slow wind. PSP crossed the HCS two times, namely at 2018/11/03 UT 01:02 and 2018/11/08 UT 19:09 with perihelion occuring on the south of side of the HCS. We predict the plasma state along the PSP trajectory, which shows a dominant proton parallel temperature causing the plasma to be firehose unstable.