This term is used both as a process and as an amount of mass added. Semantically speaking these are two distinct concepts (e.g., accumulation results in accumulation_amount of ice or snow gain), though accumulation_amount would more likely be an attribute. The scope of this term varies depending on the definition. Some definitions constrain themselves snow or ice added to glaciers; while others also include ice fields, snow cover, and/or floating ice. How to resolve this depends on the scope desired. Some definitions include additional discussion of the the physics involved which would be useful for connecting glacier ontologies to atmospheric, hydrologic, etc. ontologies. This information should be captured no matter how the inconsistencies above are resolved.