We have developed a new data structure for the efficient representation of sparse, time-varying volumetric data discretized on a 3D grid. Our “DB+Grid” , so named because it is a Dynamic Blocked Grid that shares several characteristics with B+Trees (typically employed in databases and file systems), exploits the spatial coherency of time-varying data to separately and compactly encode data values and grid topology. DB+Grid allows for cache-coherent and fast data access into sparse, 3D grids of very high resolution, exceeding millions of grid points in each dimension. Additionally, DB+Grid is very general, since it imposes neither topology restrictions on the
sparsity of the volumetric data nor access patterns when the data are inserted, retrieved or deleted.