# MUSICA WASM — Global Surface Chemistry

MICM solves a NOx–O3 mechanism independently in every cell of a global surface grid. A prescribed, non-divergent wind field then transports the species between the cells. Choose a flow pattern to see how the circulation shapes the plumes. All of the work happens in WebAssembly in this browser tab.

MUSICA Version: —
MICM Version: —

Initializing MUSICA WASM module…

### Run

Grid resolution
Chemistry time step
Steps / frame 2

### Prescribed flow

Every pattern comes from a streamfunction on the cell corners. The discrete wind field is therefore divergence free, and the transport conserves mass.

### Displayed field

Shade the night side Show wind vectors Show emission sources Smooth between cells

### Numerics

Advection scheme

The first order scheme is much more diffusive. Switch between them to see how the numerical method changes the sharpness of the plumes.

### Emissions

Source strength 100%

NO is emitted in the cells that contain the labelled cities.

### Mechanism

### Surface field

### Diagnostics

Model time | —
Grid cells solved per step | —
Wall time per step | —
Chemistry / transport split | —
Peak wind speed | —
Advection substeps per step | —
Displayed field min / mean / max | —
Transport mass drift | —
Solver state | —

The mass drift measures only the advection operator. Chemistry and emissions change the NOx burden on purpose, so they are excluded from that check.