Weather and climate models include complex representations of processes that span timescales from seconds to centuries. Only parts of these processes are explicitly resolved by the prognostic equations discretised in time and space and solved by the numerics of the model dynamical core. Unresolved subgrid-scale transport ("turbulence'') and diabatic processes such as radiative transfer, chemistry and cloud processes have to be parametrized and then solved separately by sub-models, the physical parametrizations, which have their own simplified equations, own hypotheses and often own numerical solvers. More generally, realistic modelling of any complex geophysical fluid can be achieved in practice only by splitting the full complexity of the system into individual processes. Then, a consistent, accurate and efficient coupling between the processes is essential in order to ensure the correct representation of all the feedback mechanisms that control the evolution of geophysical fluids.
The coupling between the different geophysical components in a global Earth system model is also subject to similar problems, in particular in terms of thermodynamic consistency and more generally the numerical treatment of processes across the interfaces between atmosphere, hydrosphere, cryosphere and biosphere.
Consequently, the scope of the workshop extends beyond the coupling between an atmospheric dynamical core and its physical parametrizations. It also includes a discussion about optimal strategies for coupling processes in and/or between the different component models of the Earth system. Of particular interest for this workshop are contributions with a focus on the interactions of physical modules across Earth system components and the numerics of the coupling.
The PDC22 workshop will provide a forum to share experiences and ideas on the following topics:
Conceptual issues in model or process formulation, including conservation and consistency
Discretization of individual processes and process interactions
Solution sensitivity to static or dynamic adaptation in spatial and temporal resolutions
Test strategies, results, and intercomparisons
Optimization, algorithmic efficiency and high-performance computing