Searching for waves on Jupiter's magnetopause

Abstract

The magnetosphere of Jupiter is the largest object inside the heliosphere, with a volume equivalent to 70,000 times that of the Sun. If Jupiter's magnetosphere were visible in the sky, it would be bigger than the Moon. This vast region has been observed by numerous spacecraft since the dawn of space exploration and is still being investigated to this day. In this master's thesis, we examine the boundary between the Jovian magnetosphere and the interplanetary space: the magnetopause. We analyse the measurements of various spacecraft to search for waves on its surface, and discuss their potential origin.

In Chapter 1, we present theoretical notions necessary for the comprehension of this work. We introduce the magnetosphere of Jupiter and its inner dynamics, along with our boundary of interest: the magnetopause. Afterwards, we take an interest in the different mechanisms that create boundary waves on its surface. We then introduce the model of magnetopause used throughout the entire work, dependent on the solar wind dynamic pressure.

Chapter 2 contains the presentation of the different space missions and their related magnetic field data. We also exhibit their different trajectories around Jupiter, and we establish the list of magnetopause crossings essential for the following computations.

In Chapter 3, we introduce the five different boundary analysis methods that enable us to calculate the normal to the Jovian magnetopause, with two possible options for the choice of the window of operation.

We present these computed normals for the dawn and dusk sides of Jupiter's magnetosphere in Chapter 4, along with the statistical results for the crossings of all the spacecrafts combined. Afterwards, we take an interest in specific cases of consecutive crossings that we study in detail in Chapter 5.

Chapter 6 allows us to address the reliability of our results and methods, and to question them in the context of the different mechanisms creating waves on the Jovian magnetopause.

Last but not least, we conclude on our results and evoke the potential perspectives for future improvements of the detection and characterisation of boundary waves on Jupiter's magnetopause.