PALM-meteo: universal meteorological input processor for the PALM model

PALM-meteo is an open-source modular tool for creating the so-called dynamic driver – the input file for PALM with initial and boundary conditions (IBC) and other time-varying data. Correctly selected and prepared meteorological inputs are essential for realistic PALM simulations, as will be demonstrated.

PALM-meteo can select relevant data from large input datasets. It performs geographic conversions, horizontal and vertical interpolation, temporal disaggregation and interpolation, pressure adaptation, unit conversions as well as other calculations among meteorological and chemical variables.

The horizontal interpolation phase uses either bilinear interpolation for rectangular grids or Delaunay triangulation together with barycentric interpolation for the icosahedral or unstructured grids. An important part of its processing is the vertical adaptation method, which enables terrain matching at the bottom while avoiding unrealistic vertical shifts in the higher levels. As part of creating boundary conditions it performs the necessary mass balancing.

Currently, PALM-meteo contains input modules for the mesoscale weather models WRF, ICON, Aladin and the chemical transport models CAMx and CAMS, as well as user-defined synthetic inputs. More input modules are coming soon, thanks to its modular and extensible architecture.

The tool will be presented together with input and output data from example PALM simulations. The aspects of selecting and configuring meteorological inputs will be discussed.