🏭 Gaussian Plume Dispersion Map (2D)

This 2D companion solves the same Gaussian-plume dispersion equation as the 3D version, but rather than watching individual smoke particles orbit a 3D stack, it renders the exact analytic ground-level concentration field from directly overhead: a heatmap recomputed every time a control changes, using Briggs rural neutral-stability dispersion coefficients for the plume's lateral and vertical spread. A rotating wind-direction arrow and a plume that visibly bends across the map make it obvious how the source, the receptor and the wind vector relate to each other — something that's harder to read from an orbiting 3D camera. A new stack-height control (absent from the 3D version) demonstrates a genuinely counter-intuitive result of the model: taller stacks push the ground-level concentration peak farther downwind and lower its magnitude, because the plume has to disperse vertically before it reaches ground level.