LASP Magnetosphere Seminars

Abstract

Parker Solar Probe (PSP) performs Venus gravity assists (VGAs) in order to lower its perihelion. The state-of-the-art instruments carried by PSP, including a full plasma wave package (FIELDS), provide the rare opportunity to study plasma wave activity in Venus’s induced magnetosphere. These plasma waves provide key insight to the overall dynamics of the system, including the occurrence of kinetic instabilities, magnetotail reconnection, magnetosheath turbulence and the possible presence (or lack) of lightning. 

I will discuss the plasma wave observations from PSP FIELDS during VGAs 1 – 5.  We comprehensively identified Langmuir, ion acoustic, whistler-mode and ion cyclotron waves during these VGAs and mapped the location and properties of these waves throughout near-Venus space. We compared the FIELDS instrumentation capabilities to the capabilities of the plasma wave instruments onboard Pioneer Venus Orbiter’s (PVO) and Venus Express (VEX). We found that these previous Venus missions were often unable to conclusively identify plasma wave modes or measure important characteristics of these waves, such as the propagation direction, bandwidth and maximum power. These results highlight the value of a plasma wave instrument on a new Venus mission. 

I will also discuss a case study of whistler-mode waves detected in Venus’s induced magnetotail during PSP’s fourth VGA. We find that these whistler-mode waves propagate towards the planet and were likely generated by magnetotail reconnection. Whistler-mode waves in Venus’s ionosphere and near-Venus space are often attributed to lightning as a generation mechanism, but the magnetotail whistler-mode waves detected by PSP are incompatible with a lightning source. I will discuss the implications of these results for lightning occurrence rates on Venus.