Abstract
High-accuracy estimation of the net primary production (NPP) of vegetation is important in the study of the carbon cycle and the biotic response to climatic warming. This study estimated the NPP of vegetation using Advanced Earth Observing Satellite-II/Global Imager (GLI) data with a modified vegetation index based on the universal pattern decomposition method.
The NPP was estimated using GLI 250-m data sets and ground observations of air temperature and solar radiation. The results agreed with the NPP calculation from forest survey data gathered in Nara, Japan, within the limit of estimation error.
The annual NPP was estimated using v210 global mosaic data, air temperature data from the European Centre for Medium-range Weather Forecasts, and GLI photosynthetically active radiation (PAR) data. The result was compared to the NPP calculated by the light-use efficiency-based method using the normalized difference vegetation index (NDVI). The NPP for the latter was less than in our results for areas near the equator. This difference may be due to the NDVI saturation for dense vegetation.
Using the GLI PAR data, the global annual NPP was estimated at 60.8±15.8PgCyr-1. This value is similar to that reported by the Intergovernmental Panel on Climate Change (59.9 and 62.6PgCyr-1)31) and the Moderate-resolution Imaging Spectroradiometer group (56.04 PgCyr-1)32).
