Ozone Hole Reaction-Diffusion Field: Polar Vortex Chlorine Chemistry (2D)

Stratospheric Field Drivers

UV photolysis rate 50%

Cl catalyst loading 12

Reaction rate constant k 1.0×

Polar vortex strength 90%

Turbulent mixing (diffusion) 60%

Simulation speed 1.0×

Live Readouts

O₃ remaining (domain)

100%

Ozone hole area

0.0%

Cumulative catalytic destructions (ClO+O→Cl+O₂ integral)

0.0

Avg. chain length per Cl unit

0.0

Legend

O₃ concentration (low → high) Isolated polar vortex boundary

How it works

This is a genuine two-dimensional counterpart, not the 3D particle-collision model flattened: instead of tracking discrete O₃/O/Cl/ClO "molecules" bouncing inside a box, this simulator solves the actual mass-action reaction-diffusion equations for continuous concentration fields on a latitude–altitude grid, updated every frame by explicit finite differences:

∂[O₃]/∂t = −k₁[Cl][O₃] − k_uv[O₃] + k_rec[O] + D∇²[O₃]
∂[O]/∂t  =  k_uv[O₃] − k₂[ClO][O] − k_rec[O]      + D∇²[O]
∂[Cl]/∂t = −k₁[Cl][O₃] + k₂[ClO][O]               + D∇²[Cl]
∂[ClO]/∂t=  k₁[Cl][O₃] − k₂[ClO][O]               + D∇²[ClO]

The catalytic cycle itself is the same Rowland–Molina chemistry as the 3D model (Cl + O₃ → ClO + O₂, then ClO + O → Cl + O₂, net O₃ + O → 2 O₂ with Cl unchanged) — but here it is computed as real reaction rates acting on a spatial field with actual Fickian diffusion (∇² Laplacian, solved by 5-point finite differences with zero-flux boundaries), not particle proximity checks. That field view exposes something a well-mixed particle box cannot: a genuine polar vortex. The shaded region near the top of the grid runs both a boosted reaction rate (representing the cold-temperature-activated heterogeneous chemistry on polar stratospheric cloud surfaces) and suppressed diffusion at its edge (the real vortex acts as a transport barrier, cutting the region off from ozone-rich mixing at lower latitudes) — the two effects together are why the actual Antarctic ozone hole forms as a localized, sharply-bounded feature rather than a uniform global thinning.

UV photolysis rate — sets k_uv, how fast O₃ splits into O + O₂, the atomic-oxygen source both the natural Chapman cycle and the Cl cycle depend on.
Cl catalyst loading — total chlorine (as Cl + ClO) seeded into the domain; conserved exactly by the reaction terms above, so raising it makes destruction faster without ever "running out" of catalyst.
Reaction rate constant k — scales k₁ and k₂ together, a stand-in for Arrhenius temperature dependence.
Polar vortex strength — how strongly the shaded region boosts reaction rate and isolates itself from diffusive mixing; at 0% the field behaves like a uniform well-mixed atmosphere and no local hole forms.
Turbulent mixing (diffusion) — the background diffusion coefficient D; higher values replenish depleted regions faster from their surroundings, everywhere the vortex isn't isolating them.
Ozone hole area — fraction of the grid where local O₃ has fallen below half its initial value; a metric with no equivalent in the 3D particle model, since "area" only means something once the phenomenon lives on a spatial field.

Dashed outline = polar vortex boundary

O₃-rich Partially depleted Ozone hole (O₃ < 50%)