Paragliding Air Flow
Browser-based atmospheric simulations for paragliding site analysis — thermal convection and orographic wind flow over real terrain
Thermal convection
Thermal
Pre-computed · 2D heatmap
Computes surface heat flux from solar geometry, terrain slope, land
cover (ESA WorldCover), and atmospheric transmittance. The ground
temperature anomaly is resolved per-cell and converted to a thermal
strength index — fast enough to run a full day of hourly snapshots
in seconds.
Outputs: surface temperature anomaly · thermal
index · shadow mask · sun elevation
NS
Thermal NS
3D Navier-Stokes · Boussinesq · LES
Full 3D incompressible Navier-Stokes solver under the Boussinesq
approximation: solar heating warms the ground, which injects
buoyancy into the boundary layer, driving convective thermal plumes.
Smagorinsky LES turbulence closure and a Red-Black SOR pressure
solver. Runs in a Web Worker; takes minutes for a coarse grid.
Outputs: 3D temperature anomaly θ' · vertical wind
w · convergence · cross-section slices
Orographic wind
Wind
2D Shallow Water Equations · explicit FD
Solves the 2D shallow water equations (SWE) with reduced gravity
over real terrain. The atmosphere is modelled as a single layer of
depth h flowing over the orographic floor. Terrain-blocking,
orographic lifting, Froude number transitions, hydraulic jumps, and
vorticity wakes emerge naturally. Runs to quasi-steady state in
seconds to minutes.
Outputs: wind speed · vertical wind proxy · Froude
number · vorticity · flow depth
NS
Wind NS
3D Navier-Stokes · log profile · land-cover roughness
Full 3D incompressible Navier-Stokes solver for mechanical wind
flow. Terrain cells are blocked (no-slip); inflow uses a logarithmic
wind profile anchored to a per-cell roughness length z₀ derived from
ESA WorldCover. Semi-Lagrangian advection and a Jacobi pressure
Poisson solver. Resolves lee-side recirculation, flow separation,
and surface-layer structure.
Outputs: 3D velocity (U, V, W) · surface wind speed
· vertical wind · pressure · vorticity