Recently, the Climate Forecasting (CF) conventions have been extended to support GRIDSPEC data spread over multiple files, covering both time and space aggregation. These extensions cover mosaic data on the cubed-sphere, in particular, with its six tiles connected in unstructured fashion. Mosaic data are ideally suited for parallel processing, either on a per tile basis or within a tile using a standard domain decomposition. We show examples of parallel processing using the Python Climate Data Analysis Tools (CDAT) software for a use-case involving interpolation over a region containing a corner point between three tiles. The examples leverage CDAT's recently added capability to understand GRIDSPEC data layouts, and the ability of CDAT variables to interact with C code (LibCF) and play with the Python mpi4py module.