Mapping Global Leaf Inclination Angle (LIA) Based on Field Measurement Data

Leaf inclination angle (LIA), the angle between leaf surface normal and zenith directions, is a vital parameter in radiative transfer, rainfall interception, evapotranspiration, photosynthesis, and hydrological processes. This study generated the global first 500 m mean LIA (MLA) product by gap-filling the LIA measurements. The results show that MLA increases with the rise of latitude. Cereal crops show the highest MLA (54.9°) while evergreen broadleaf forest has the lowest MLA (36.9°). The global vegetation MLA is 46.6° and the MLA of broadleaf forests is less than that of other plant functional types. The global MLA product has a medium consistency with the upscaled MLA samples (R
²
= 0.58, RMSE = 6.89°). The product enhances our understanding of global LIA and should greatly assist remote sensing retrieval and land surface modeling studies.