Technical note: Recursive rediscretisation of geo-scientific data in the Modular Earth Submodel System (MESSy)

Abstract. This technical note describes a method for the rediscretisation of "gridded" geo-scientific data. A recursive algorithm (NREGRID) is derived to solve the rediscretisation problem for orthogonal grids (including curvilinear) of arbitrary dimension. The algorithm is used within the program NCREGRID to handle geo-scientific data. These data are typically 2-dimensional (latitude-longitude grid), or 3-dimensional (latitude-longitude grid with a vertical pressure, or hybrid pressure coordinate, as used in atmospheric modelling). NCREGRID can be used as stand-alone program for the transformation ("regridding") of data from and to data files in netCDF format. Moreover, NCREGRID constitutes the core of the Modular Earth Submodel System (MESSy) data import interface, providing a powerful tool for accessing data independently of the applied grid resolution ("automatic regridding").