glob·al/glōbəl/ Adjective (adverb globally)
of, relating to, or involving the entire world :
worldwide <a global system of communication>;
also : of or relating to a celestial body (planet).
ORIGIN French (1670 AD), globe + -al "worldwide, universal".

albedo/albeedo/ noun (pl. albedos)(chiefly Astronomy)
The proportion of the incident light that is reflected by a surface or ratio of light reflected from a surface.
ORIGIN Latin (1859 AD), L. albedo, lit. "whiteness" from albus "white".

fraction of Absorbed Photosynthetically Active Radiation (fAPAR) is the fraction of the incoming radiation in the 400-700 nm band absorbed by the leaves, which can be used for photosynthesis. Definitions differ according to illumination conditions and leaf state.

Leaf Area Index (LAI) is defined as the one-sided green leaf area per unit ground surface area (with extensions for needle-leaf trees). It is a unitless quantity (m2m-2). Depending on the retrieval method, its exact definition varies. BHR-TIP retrieves effective LAI, consistent with existing implementations in large-scale climate and Earth system models, and is related to "true" LAI through a canopy-dependent structure factor.