Currently, atmospheric general circulation models (GCMs) discretize separately the processes described by the adiabatic equations driving the evolution of the grid-scale variables (the “dynamics”) and the bulk or statistical parameterizations of the mean effects of the subgrid and/or diabatic processes (the “physics”). These two components then need to be coupled to each other. This coupling of physics parameterizations to the resolved fluid dynamics (the dynamical core) is an important aspect of geophysical models. However, often model development is strictly segregated into either physics or dynamics, and the coupling is often guided by technical convenience rather than analysis (Williamson 2007). Hence, this area has many more unanswered questions than in-depth understanding. Furthermore, recent developments in the design of dynamical cores (significant increase in resolution, move to nonhydrostatic equation sets, variable resolution, and adaptive meshes, etc.), extended process physics (prognostic microphysics, 3D turbulence, nonvertical radiation, etc.), and predicted future changes of the computational infrastructure (e.g., exascale with its stronger need for task parallelism, data locality, and asynchronous time stepping) add even more complexity and new questions. To address these issues the first Physics Dynamics Coupling (PDC14) workshop (http://pdc.cicese.mx) was held in December 2014. The highlights and motivation of PDC14, which took place in Ensenada, Baja California, México, are summarized below.
