2D Mantle Convection: Grid-Based Thermal Plumes

This is the 2D companion to the 3D mantle convection simulator. It runs the same real Boussinesq buoyancy physics — a finite-difference temperature field heated from below and cooled from above, coupled to a vorticity-streamfunction velocity field so hot material genuinely rises and cold material genuinely sinks — but renders and interacts with it through a completely different pipeline: a CPU-computed grid painted straight onto a 2D canvas, hundreds of Lagrangian tracer particles advected through the same flow to trace real particle paths, a live quiver overlay showing flow direction and strength, and a click-to-seed plume injector for perturbing the field by hand. The result is the same class of Rayleigh-Bénard convection cells and rising thermal plumes that drive plate tectonics in Earth's real mantle, viewed and explored a different way than the 3D shader render.