Recent advances in understanding substorm dynamics

Magnetospheric substorms are elemental processes of solar wind energy storage and explosive release in Earth's magnetosphere. They encompass fundamental plasma physics questions, are ubiquitous during all types of geomagnetic conditions, contribute significantly to magnetic storms, and are a key element of Space Weather applications. This paper reviews recent major advances enabled by modern multi‐point space‐based and ground‐based platforms. These datasets have also empowered a system‐wide perspective and advanced modeling. We particularly highlight progress in two areas: (1) substorm onset timing and evidence for current sheet preconditioning and destabilization and (2) fast flows and dipolarizations, including the role of entropy in magnetotail plasma propagation. Key Points Different processes interact to initiate the substorm onset and auroral breakup Multi‐scale disturbances result in, possibly, multiple paths to onset Flow bursts as the bubbles, important role of entropy in flow burst dynamics