[CIG-ALL] ASPECT 2.2.0 released

[Rene Gassmoeller]

We are pleased to announce the release of ASPECT 2.2.0. ASPECT is the
Advanced
Solver for Problems in Earth's ConvecTion. It uses modern numerical
methods such
as adaptive mesh refinement, multigrid, and a modular software design to
provide a fast, flexible, and extensible mantle convection solver. ASPECT is
available from

                   https://aspect.geodynamics.org/

and the release is available from

        https://geodynamics.org/cig/software/aspect/

and

        https://github.com/geodynamics/aspect/releases/tag/v2.2.0

This release includes the following significant changes:

- New: There is a new matrix-free Stokes solver which uses geometric
multigrid.
  This method is significantly faster than the default algebraic multigrid
  preconditioner and uses less memory. Free surface and melt transport
are not
  yet implemented.
  (Thomas C. Clevenger, Timo Heister)

- New: There is now a new approximation for the compressible convection
  models that is called 'projected density field'.
  (Rene Gassmoeller, Juliane Dannberg, Timo Heister, Wolfgang Bangerth)

- Changed: The Geodynamic World Builder has been updated to version 0.3.0.
  (Menno Fraters)

- Changed: ASPECT now requires deal.II version 9.0.0 or newer.
  (Timo Heister, Rene Gassmoeller)

- New: There is a new, alternative stabilization method for the
advection equation
  called SUPG.
  (Thomas C. Clevenger, Rene Gassmoeller, Timo Heister, Ryan Grove)

- Changed: The entropy viscosity method for stabilizing the advection
equations
  was substantially improved leading to less artificial diffusion in
particular
  close to boundaries.
  (Rene Gassmoeller)

- New: The 'visco plastic' material model now has an option to simulate
  viscoelastic-plastic deformation. The 'viscoelastic plastic' material
  model has been superseded and removed.
  (John Naliboff, Dan Sandiford)

- New: The "Free surface" functionality has been generalized and is now
part of
  "Mesh deformation". This change is incompatible to old parameter files
that
  used the free surface.
  (Rene Gassmoeller, Anne Glerum, Derek Neuharth, Marine Lasbleis)

- New benchmarks: entropy equation, viscoelastic cantilever, bouyancy-driven
  viscoelastic plate stress, advection in annulus, slab detachment
benchmark,
  several advection benchmarks, rigid shear, polydiapirs, surface loading.
  (Wolfgang Bangerth, Fiona Clerc, Juliane Dannberg, Daniel Douglas, Rene
  Gassmoeller, Timo Heister, Garrett Ito, Harsha Lokavarapu, John Naliboff,
  Elbridge G. Puckett, Cedric Thieulot)

- Incompatibility: The option to use PETSc for linear algebra has been
removed
  until further notice.
  (Timo Heister)

- New: If the user has the libdap libraries installed then input data can be
  pulled from the server instead of a local file.
  (Kodi Neumiller, Sarah Stamps, Emmanuel Njinju, James Gallagher)

- New: Implement the "no Advection, single Stokes" and
  "single Advection, iterated Newton Stokes" solver schemes.
  (Timo Heister, Anne Glerum)

- New: The chunk geometry model can now incorporate initial
  topography from an ascii data file.
  (Anne Glerum)

- New: The 'depth average' postprocessor now additionally computes the
laterally
  averaged density of vertical mass flux for each depth slice in the model.
  (Rene Gassmoeller)

- Changed: The gravity point values postprocessor has been significantly
extended.
  (Ludovic Jeanniot, Cedric Thieulot)

- New: There is now a general class
  `MaterialModel::Utilities::PhaseFunction` that can be used to model
  phase transitions using a smooth phase function.
  (Rene Gassmoeller, John Naliboff, Haoyuan Li)

- New: ASPECT now includes a thermodynamically self-consistent compressible
  material model, that implements the Modified Tait equation of state
that is
  described in Holland and Powell, 2011.
  (Bob Myhill)

- New: The material models can now outsource the computation of the
viscosity
  into a separate rheology model.
  (Rene Gassmoeller)

- New: ASPECT now includes initial temperature and initial composition
plugins
  that use ASCII data files to define the initial temperature or composition
  at a series of layer boundaries.
  (Sophie Coulson, Anne Glerum, Bob Myhill)

- New: Extended spherical shell geometry model to include custom mesh
schemes.
  (Ludovic Jeanniot, Marie Kajan, Wolfgang Bangerth)

- New: There is a new termination criterion that cancels the model run
  when a steady state average temperature is reached.
  (Rene Gassmoeller, Juliane Dannberg, Eva Bredow)

- Bug fixes to : parallel hdf5 output, chunk geometry model, initial
  topography modules, gplates boundary velocity plugin.
  (many authors)

A complete list of changes and their contributing authors can be found at
 
https://aspect.geodynamics.org/doc/doxygen/changes_between_2_81_80_and_2_82_80.html

Wolfgang Bangerth, Juliane Dannberg, Rene Gassmoeller, Timo Heister,
Jacqueline Austermann, Menno Fraters, Anne Glerum, John Naliboff,
and many other contributors.