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Tearing mode

A plasma instability in which a perturbed sheared magnetic field reconnects across a resonant layer, producing magnetic islands.

Version
v1 · 2026-09-28 · History
Domain-specific #
12473
Domain group
Natural Sciences
Origin domain
Physics
Subdomain
Plasma Physics → Physics
Aliases
Tearing instability

Core Idea

A tearing mode is a particular instability of a magnetized plasma. A perturbation of a sheared magnetic equilibrium grows around a resonant or current layer. Within that localized region, departures from ideal magnetic-field behavior permit field lines to reconnect; the new topology is commonly expressed as magnetic islands. This distinguishes the mode from a fluid-shear vortex or an ideal magnetic displacement that preserves field connectivity.

The frozen article names reconnection and islands but is a very short and uneven authority surface. A university magnetohydrodynamics lecture supports the classical distinction between nearly ideal outer plasma and a narrow non-ideal layer. The frozen page's isolated '100 nanoseconds' growth time is not portable across machines or parameter regimes, and its Types list includes unrelated instabilities; neither is adopted as a defining fact. Islands can alter transport, but the term does not guarantee a full disruption in every setting.

Scope of Application

These uses require a growing magnetic perturbation with field-line reconnection, not merely any plasma instability.

  • Plasma-mode classification. Separate tearing topology change from ideal displacement or hydrodynamic instability.
  • Magnetic confinement interpretation. Read island observations as evidence of reconnecting field structure, not automatic total disruption.
  • Model comparison. Keep the classical resistive-layer mechanism distinct from broader non-ideal variants.
  • Source auditing. Reject unsupported time scales and misleading umbrella lists when identifying a mode.

Clarity

Look for a sheared plasma magnetic field, a growing perturbation near a resonant/current layer, and reconnection that produces island topology. Inclusion: A classical resistive tearing island fits. Exclusion: A Kelvin–Helmholtz vortex or an ideal displacement without reconnection does not. Nearest boundary: Magnetic reconnection alone may lack the growing tearing mode. No universal 100-nanosecond growth time or inevitable full disruption is supported.

Manages Complexity

The mode label joins field geometry, local non-ideal behavior, perturbation growth, and new connectivity in one test. It prevents nearby instability names from being conflated, while leaving scale, detailed growth law, and disruption outcomes to the actual plasma regime.

Abstract Reasoning

  1. Identify the reference sheared magnetic configuration and perturbation class.
  2. Locate the resonant/current region where ideal connectivity can fail.
  3. Check that the disturbance grows as an instability rather than passive diffusion.
  4. Look for reconnected field-line topology and its island manifestation.
  5. Bound any transport, timescale, or disruption statement to the modeled configuration.

Knowledge Transfer

The equilibrium–perturbation–growth test transfers from the live instability prime, but the tearing label travels only to magnetic plasmas with reconnection and island topology. A fluid vortex, ideal displacement, or generic reconnection event shares at most part of that structure; the frozen page's one numerical timescale transfers nowhere without conditions.

Relationships to Other Abstractions

Local relationship map for Tearing modeParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Tearing modeDOMAINPrime abstraction: Instability — is a kind ofInstabilityPRIME

Current abstraction Tearing mode Domain-specific

Parents (1) — more general patterns this builds on

  • Tearing mode is a kind of Instability Prime

    Tearing modes specialize instability to growing magnetic perturbations that reconnect sheared plasma field lines and form islands.

Hierarchy paths (2) — routes to 2 parentless roots

Neighborhood in Abstraction Space

Tearing mode sits in a sparse region of the domain-specific corpus (63rd percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Geophysical Wave & Flow Parameters (11 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08