A Lagrangian advection scheme with shape matrix (LASM) for solving advection problems
A new Lagrangian advection scheme with shape matrix (LASM) is proposed to take advantage of the extreme low numerical diffusion of the Lagrangian methods. The tracer is discretized into finite parcels, which move along the downstream trajectories. Different from other Lagrangian schemes, the parcel...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-12-01
|
| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/7/2951/2014/gmd-7-2951-2014.pdf |
| Summary: | A new Lagrangian advection scheme with shape matrix (LASM) is proposed to
take advantage of the extreme low numerical diffusion of the Lagrangian
methods. The tracer is discretized into finite parcels, which move along the
downstream trajectories. Different from other Lagrangian schemes, the parcel
shape is simulated explicitly by a linear transformation matrix. By doing so,
the aliasing error in the Lagrangian schemes is largely reduced without
introducing substantial interparcel mixing in the pure advection stage,
because the flow information will be respected when remapping tracer density
onto the fixed model grids. An adaptive interparcel mixing algorithm is
constructed to ensure the validity of the linear approximation of the parcel
shape, where the mixing is only triggered when it is necessary and resembles
the physical mixing. The total tracer mass on the parcels is conserved
exactly. The new scheme is validated by using several test cases. |
|---|---|
| ISSN: | 1991-959X 1991-9603 |