Publications

Yang, Yuting; Guan, Huade; Shang, Songhao; Long, Di; Simmons, Craig T. (2014). Toward the Use of the MODIS ET Product to Estimate Terrestrial GPP for Nonforest Ecosystems. IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, 11(9), 1624-1628.

Abstract
Moderate Resolution Imaging Spectroradiometer (MODIS) gross primary production (GPP) data (MOD17), based on the light-use-efficiency algorithm, have been widely used to assess large-scale carbon budgets. However, systemic errors of this product have been reported, particularly for nonforest ecosystems. Here, we test a simple and operational way to estimate GPP in nonforest ecosystems by inverting the MODIS evapotranspiration (ET) product (MOD16) using ecosystem water use efficiency (WUE = GPP/ET). Field measurements from 17 nonforest Ameri-Flux sites of GPP were used for validation. Results show that the inverted GPP from MOD16 (MOD16 GPP) agrees better with the observed GPP than MOD17 does. The overall root-mean-square error (RMSE) and mean bias of MOD16 GPP are 19.63 g C/m(2)/ 8-day and-4.06g C/m(2)/8-day, respectively, which are lower than the corresponding values of MOD17 GPP (RMSE = 23.82 g C/ m(2)/8-day and mean bias = -9.07 g C/m(2)/8-day). This finding suggests the potential to achieve a better assessment of GPP for nonforest ecosystems with a fine resolution.

DOI:
10.1109/LGRS.2014.2302796

ISSN:
1545-598X; 1558-0571