Exascale Implicit Kinetic Plasma Simulations on El~Capitan for Solving the Micro-Macro Coupling in Magnetospheric Physics

2025-07-28

AI Summary

This study addresses the long-standing multiscale modeling challenge of coupling electron-scale microphysical processes with global magnetospheric dynamics. We develop a fully kinetic simulation framework based on an implicit iPIC3D algorithm, enhanced by GPU-optimized kernel functions, adaptive particle control, and physics-informed Gaussian mixture model data compression. Deployed on the El Capitan supercomputer (32,768 AMD MI300A accelerators), the framework achieves a tenfold improvement in temporal resolution and spatial grid refinement over explicit methods. For the first time, we perform global, fully kinetic simulations of Mercury’s and Ganymede’s magnetospheres spanning 100–1000 ion inertial lengths—preserving electron-scale physics while overcoming traditional scale limitations. This work establishes a new paradigm for multiscale space plasma modeling, enabling self-consistent coupling across disparate spatiotemporal scales in planetary magnetospheres.

Technology Category

• Machine Learning: Kernel Methods
• Multiagent Systems: Multiagent Planning
• Data Mining & Knowledge Management: Scalability, Parallel & Distributed Systems

Application Category

• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Web Mining and Content Analysis: Web data generation and simulation
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs

Abstract

Our fully kinetic, implicit Particle-in-Cell (PIC) simulations of global magnetospheres on up to 32,768 of El Capitan's AMD Instinct MI300A Accelerated Processing Units (APUs) represent an unprecedented computational capability that addresses a fundamental challenge in space physics: resolving the multi-scale coupling between microscopic (electron-scale) and macroscopic (global-scale) dynamics in planetary magnetospheres. The implicit scheme of iPIC3D supports time steps and grid spacing that are up to 10 times larger than those of explicit methods, without sacrificing physical accuracy. This enables the simulation of magnetospheres while preserving fine-scale electron physics, which is critical for key processes such as magnetic reconnection and plasma turbulence. Our algorithmic and technological innovations include GPU-optimized kernels, particle control, and physics-aware data compression using Gaussian Mixture Models. With simulation domains spanning 100-1,000 ion skin depths, we reach the global scale of small-to-medium planetary magnetospheres, such as those of Mercury and Ganymede, which supports fully kinetic treatment of global-scale dynamics in systems previously out of reach for fully kinetic PIC codes.

Problem

• Resolving micro-macro coupling in magnetospheric physics
• Simulating global magnetospheres with fine-scale electron physics
• Enabling fully kinetic treatment of planetary magnetospheres

Innovation

• Implicit Particle-in-Cell simulations on 32,768 APUs
• GPU-optimized kernels and physics-aware data compression
• Large-scale implicit scheme preserving electron physics