LightAMR format standard and lossless compression algorithms for adaptive mesh refinement grids: RAMSES use case

•Lack of standardized format for Adaptive Mesh Refinement post-processing tools.•LightAMR is a new compact way to fully describe Adaptive Mesh Refinement meshes.•Tree pruning algorithm for data redundancy can be built over the lightAMR format.•LightAMR mesh description is compressible by a factor ∼1000 on RAMSES uses cases.•Lossless compression of lightAMR float scalar fields achieves a ratio of 1.2-1.5.