Phenology is the study of inter-annual biotic cycles. Phenological processes in plants are driven mainly by climate. In turn, plant phenology affects cycling of energy, water, and nutrients, as well as seasonal animal behavior. The terraPulse suite of phenology datasets are derived from time-serial measurements of the Normalized Difference Vegetation Index (NDVI) in each pixel. To improve representation in temperate, boreal, and arctic regions, data can be masked for snow upon request.