Approximation of the buoyancy term

The buoyancy term (right-hand side of the momentum equation) always uses the density that is provided by the material model (see Material models). Depending on the material model, this density could for example depend on temperature and pressure (such as in ALA), or on temperature and depth (as in TALA); and the model can also be set up in a way that it uses density deviations from a reference state instead of a full density (see Static or dynamic pressure?).

Note

In the current version of ASPECT, it is the responsibility of the user to select a material model that is consistent with the formulation they want to use in their model. In the future, we plan to make it more obvious which approximations are supported by a particular material model.