Abstract
Leaf Area Index (LAI) is an important parameter as assimilation and validation data of the global ecosystem models. Recently several organizations have developed the satellite-based global LAI datasets that are publicly available. However their algorithms, definitions, and uncertainties are slightly different. The objective of this paper is to review the definition, uncertainty, and validation method of the currently available global LAI datasets derived from satellite (ISLSCPII, Boston Univ., GLOBCARBON, MOD15, CYCLOPES). The LAI estimation approaches (vegetation index, and radiative transfer inversion) are firstly described. Then LAI estimation algorithms and validation methods are summarized. The review of the validation activities point out that the recent validation studies are still insufficient both to cover globally and to warrant the LAI seasonality, indicating further validations and algorithm refinements.
