Optimization of a minimal-storage strategy for cloud amount data

A strategy is proposed which reduces the storage requirements for cloud amount information by up to 50%. Archiving only the mean cloud amount, μ, is recommended. Retrieval of most of the original data is possible if observations are made at high resolution (≲ 1 km) and the processing system gives rise to predominantly binary (i.e. cloud or no-cloud) information. The strategy is applicable to cloud amount at any level and to total cloud cover. One year's global cloud data can be stored on 2.5 computer magnetic tapes in contrast to the 13 tapes suggested by GARP/JOC (1980) and ISCCP (1982). The resultant new cloud archive will have the advantage of being equally useful for all scientific users (e.g. remote sensing and climate modelling groups) and each group's post-processing time will be greatly reduced.