Alfven

Alfven is a computational toolkit and interactive dashboard for EF2240 Space Physics. It bridges the gap between theoretical magnetohydrodynamics (MHD) and observable space weather through a highly visual, web-based interface.

The project features a Space-Themed Glassmorphism UI, where floating, translucent panels sit atop a live, 3D-rendered starfield, allowing students to manipulate plasma parameters and visualize the Earth's magnetic shield in real-time.

📚 Syllabus Mapping (EF2240)

This project strictly adheres to the course learning outcomes:

Module	Syllabus Topic	Implemented Features
Plasma State	Define and classify plasmas	Calculator for Debye Length ($\lambda_D$), Plasma Frequency ($\omega_{pe}$), and Larmor Radius ($r_L$).
The Sun	Sun and solar wind	Parker Spiral model for the Interplanetary Magnetic Field (IMF) and sunspot temperature estimation.
Magnetosphere	Model the form of the magnetosphere	Chapman-Ferraro distance calculator to determine Magnetopause location ($R_{mp}$) under solar wind pressure.
Ionosphere	Origin, structure and dynamics	Chapman Layer profiling to model Electron Density ($N_e$) vs. Altitude for D, E, and F layers.
Aurora	Power dissipated in the aurora	Current sheet estimation and Joule heating calculations for geomagnetic storms.

📊 Visualizations & Artifacts

1. The Magnetosphere (Interactive Field Tracing)

A D3.js visualization modeling the compression of Earth's magnetic field by the Solar Wind dynamic pressure. Users can adjust solar wind velocity and density via glass sliders.

Code:

from alfven.magnetosphere import Magnetopause

# Solar Wind Conditions (Normal vs Storm)
normal = Magnetopause(density=5e6, velocity=400e3) # 5 cm^-3, 400 km/s
storm  = Magnetopause(density=20e6, velocity=800e3) # CME Impact

print(f"Normal Standoff: {normal.radius_re:.1f} Re")
print(f"Storm Standoff:  {storm.radius_re:.1f} Re")

Artifact Output:

Figure 1: The Magnetosphere Standoff. The visualization renders the "Standoff Distance" where the solar wind dynamic pressure balances the Earth's magnetic pressure. Under storm conditions (red line), this boundary moves inward, potentially exposing geostationary satellites (dotted circle) to the magnetosheath plasma.

2. Ionospheric Profiling (Chapman Layers)

An interactive altitude profile showing how UV radiation creates the D, E, and F layers. The UI allows toggling "Day" vs "Night" modes to see the decay of the D-layer.

Code:

from alfven.ionosphere import ChapmanLayer

# Create E-layer (peak at 110km) and F-layer (peak at 300km)
e_layer = ChapmanLayer(h0=110, H=10, n_max=1e11)
f_layer = ChapmanLayer(h0=300, H=50, n_max=1e12)

profile = e_layer + f_layer
profile.plot_altitude_profile(0, 600)

Artifact Output:

Figure 2: Ionospheric Layers. The plot shows Electron Density ($N_e$) vs Altitude ($h$). The distinct E and F layers are visible. The dashboard uses semi-transparent fills to represent plasma density, adhering to the glassmorphism theme.

3. Solar Wind (Parker Spiral)

A top-down view of the solar system showing the spiral structure of the Interplanetary Magnetic Field (IMF).

Artifact Output:

Figure 3: The Parker Spiral. Because the Sun rotates, the magnetic field lines frozen into the radially expanding solar wind are wound into an Archimedean spiral. The visualization animates plasma parcels traveling outwards along these field lines.

4. Sunspot Temperature (Solar Physics)

Estimates the temperature of a sunspot ($T_{spot}$) based on its intensity contrast ratio ($I_{spot}/I_{phot}$) with the surrounding photosphere ($T_{phot} \approx 5778K$). Includes a dynamic visualization of the sunspot darkening.

5. Aurora Power (Auroral Physics)

Calculates the total power dissipated in the auroral ionosphere and the height-integrated sheet current, given the ionospheric electric field ($E$), Pedersen conductivity ($\Sigma_P$), and the area of the active region.

🧪 Testing Strategy

Unit Tests (Fundamental Physics)

Located in tests/unit/.

*Example: tests/unit/test_plasma.py*

def test_debye_length():
    """
    Verifies Debye Length calculation: lambda_D = sqrt(eps0 * k * Te / (n * e^2))
    """
    from alfven.plasma import PlasmaState

    # Typical Solar Wind: n=5 cm^-3, T=10 eV
    sw = PlasmaState(n=5e6, T_ev=10)

    # Expected: ~10 meters
    assert abs(sw.debye_length - 10.5) < 1.0

E2E Tests (Space Weather Event)

Located in tests/e2e/.

*Example: tests/e2e/test_storm.py*

def test_geostationary_exposure():
    """
    E2E Test: Does a severe solar storm compress the magnetopause
    inside Geosynchronous Orbit (6.6 Re)?
    """
    # Simulate Carrington-class event
    storm = Magnetopause(density=50e6, velocity=1200e3, Bz=-20e-9)

    # If radius < 6.6 Re, satellites are in the magnetosheath
    assert storm.radius_re < 6.6

⚖️ License

MIT License

Copyright (c) 2026 Dhruv Haldar