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🧪 Magnetosphere-Solar Wind Interaction (2D): Magnetopause & Aurora Model

2D companion to Magnetosphere-Solar Wind Interaction: the Shue (1997) empirical magnetopause model and dipole L-shell field-line geometry compute a real magnetopause standoff distance, reconnection electric field and auroral oval latitude live from the sliders, driving a particle-precipitation aurora.

Electromagnetism2DModerate60 FPS📱 Mobile-adapted⇄ 3D version

Details

CategoryElectromagnetism

RenderingCanvas 2D

DifficultyModerate

Target FPS60

ControlsSolar wind speed, solar wind density, IMF Bz and planetary field-strength sliders, plus Pause and Reset — a live panel shows magnetopause standoff, dynamic pressure, merging electric field, auroral oval latitude, particle energy and precipitation rate.

magnetospheresolar windmagnetopausedipole fieldaurorareconnection

Related simulations

Magnetosphere-Solar Wind InteractionThe 3D original this page is paired with.

Aurora Formation Science (2D)A related dipole-field aurora companion in the same category.

2D Lorentz Force — Charged Particle DriftAnother charged-particle-in-a-field companion in the same category. ⊞ All 177 in Electromagnetism →

This 2D companion replaces the 3D original's shared decorative template — a generic "Simulation Atlas" scene reused with cosmetic swaps across dozens of unrelated topics — with an actual magnetospheric-physics model: the Shue (1997) empirical formula sets the magnetopause standoff distance and shape from solar-wind dynamic pressure and IMF Bz, a half-wave-rectifier merging electric field gates how many particles leak in through dayside reconnection, and dipole L-shell geometry carries captured particles down real field lines to precipitate at the correct auroral-oval latitude.

⚙ Under the hood

2D Canvas magnetosphere built on the Shue (1997) magnetopause model (R₀, α from dynamic pressure and IMF Bz), the dipole L-shell field-line equation r = L·sin²θ, and a merging-electric-field-gated particle-capture and precipitation loop that colors the aurora by particle energy.

magnetospheresolar windmagnetopausedipole fieldaurorareconnection

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install

Why does the aurora only appear when IMF Bz goes negative?

Dayside magnetic reconnection — the process that lets solar-wind particles cross into the magnetosphere — only turns on efficiently when the interplanetary magnetic field points southward (negative Bz), matching Earth's own northward-pointing dayside field lines so they can merge. This companion models that with a half-wave-rectifier merging electric field: Em = v × max(0, −Bz), which is zero for northward Bz.

What decides whether the aurora glows green or red?

The simulation's particle-energy readout (from ½mv² on the solar-wind speed) sets how deep a precipitating particle penetrates before it stops: higher-energy particles reach lower altitudes where oxygen and nitrogen collisions favour green/blue emission lines, while lower-energy particles stop higher up where the red oxygen line dominates — the same ordering seen in real auroral spectra.