Earth’s magnetic field and the solar wind interact in such a manner that a cavity around the planet known as the magnetosphere forms. The magnetosphere is not a perfect shield from the solar wind; energy and momentum can be passed between the two systems at their interface - the magnetopause. The solar wind energy circulation throughout Earth’s magnetosphere leads to many technologically disruptive phenomena, collectively known as space weather. Understanding this energy source is vital for space weather impact mitigation and prediction. One example of how this energy and momentum transfer occurs is via the Kelvin-Helmholtz Instability (KHI). The KHI plays a significant role in the viscous-like mass, momentum, and energy transfer from the solar wind into the magnetosphere through its intrinsically coupled vortical and wave dynamics. These dynamics have both direct and indirect influences throughout magnetospheric regions (such as the radiation belts, auroral zones, and ionosphere) and provide different pathways for solar wind energy circulation throughout geospace. Since sparse in situ measurements cannot resolve this global problem, we employ a novel global 3D magnetohydrodynamic (MHD) simulation called Gorgon to confidently study and compare the effects of these dynamics, as only global simulations can reproduce the KHI in a representative magnetospheric environment.

In this talk, I aim to cover how a KHI vortex is formally defined and reliably identified using local pressure-minima to derive a novel vortex identification technique known as 𝜆𝑀𝐻𝐷. This technique leads to an investigation into how plasma inhomogeneity, compressibility, and magnetic tension influence the formation of an MHD vortex. Furthering this work, the spatial-temporal ambiguity associated with KHI-generated magnetopause surface waves (MSWs) is explored using a factorisation and dimensionality reduction technique known as Dynamic Mode Decomposition (DMD). Analysis using this technique reveals dominant MSW frequencies and their spatial dependences and dominances. Furthermore, it indicates that discrete frequency MSWs have a finite extent along the boundary and a superposition of modes is present showing the KHI both generates and advects MSWs and vortices. The analysis also reveals MSW effects on the magnetosphere: MSWs drive magnetosheath waves which cause bow shock motion; the KHI is present along the high-latitude magnetopause in the noon-midnight meridian; and MSWs are shown to be linked to plasma sheet waves. I conclude by discussing how this approach improves our understanding of MSWs energy transfer.