Atmospheric Convection & Pressure-Wind Simulator

Field Sources

Click / tap the grid to drop a source of the selected type. Ground heating raises local air temperature; a low-pressure center lowers local pressure. Both keep acting every frame — like sun on ground, or a real cyclone.

Parameters

Heating rate 1.0×

Coriolis (rotation) 0.0

Viscosity 0.20

Display

Max wind speed

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ΔT (max−min)

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ΔP (max−min)

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Sources

How it works

The domain is a grid of air parcels, each carrying a temperature T and pressure P. Density follows the ideal gas law, ρ = P /(R·T): hotter air at the same pressure is genuinely less dense. Every step, buoyancy pushes each parcel's vertical velocity toward g·(ρ_ref − ρ)/ρ_ref — warm, light air accelerates upward, cold, dense air sinks, exactly as in a real Rayleigh–Bénard cell. Horizontal wind is driven the same physically-grounded way: acceleration = −∇P/ρ, so air genuinely flows from high pressure toward low pressure, fastest where the pressure gradient is steepest.

ρ = P / (R·T)
dv/dt = −∇P/ρ + (0, g·(ρ_ref−ρ)/ρ_ref) − k_visc·v + Coriolis
∂T/∂t = −v·∇T + diffusion   (semi-Lagrangian advection)
∂P/∂t = −v·∇P + diffusion + relaxation toward ambient

Heat source — models solar-heated ground: raises T locally every frame, exactly like sunlight warming a patch of land or asphalt.
Low-pressure center — models a cyclone core: lowers P locally every frame, pulling surrounding air inward and, once it warms, upward.
Coriolis — a simplified rotational deflection term (a·Coriolis·(−v_y, v_x)) bends the pressure-driven wind sideways instead of letting it flow straight into the low, the same mechanism that spirals real cyclones instead of collapsing them to a point.
Viscosity — damps velocity each step; too low and the grid becomes numerically noisy, too high and circulation can't organize into a coherent cell.

What you should see: a heat source alone produces a rising plume above it with cooler air sinking and returning along the floor — a convection cell. A low-pressure center alone produces wind spiraling/flowing inward toward it. Combine both and the two circulations compete and merge, the same way real weather couples solar heating and pressure systems into fronts and storms.

Warm / high-P Cool / low-P Wind vector