Traditionally, all cells within a vertical level in MOM have the same vertical thickness. Option partial_cell allows bottom ocean cells within any given level to be of different vertical thickness so as to more accurately resolve the physical bottom (Pacanowski and Gnanadesikan, 1998). This option must be used right from the beginning of an experiment. It is not intended as an option which can be enabled in the middle of an experiment. Nor is it intended to be disabled in the middle of an experiment. Either a model is constructed using full-cells (the default) or partial-cells (option partial_cell).