| Abstract | Remote sensing is a unique approach to monitor the behavior of terrestrial ecosystems over large areas. Using remote sensed data and ancillary data, a process model, namely the Boreal Ecosystem
Productivity Simulator (BEPS), has been developed to estimate net primary productivity (NPP). It becomes a challenge to incorporate a more advanced photosynthesis model, the best known Farquhar's model, into BEPS because the Farquhar model was
initially developed for individual leaves at an instant of time. It is computationally and practically difficult for large area applications to use the model at the desired small time steps (minutes to hours). We have developed an analytical solution
to the integral of Farquhar's model that allows us to calculate net photosynthesis rate at daily steps at the canopy level. This daily model is suitable for regional remote sensing applications at moderate resolutions (250-1000 m). It is shown that
the integrated model greatly improves photosynthesis calculations. Combining the integrated Farquhar model with remotely sensed LAI, FPAR, land cover type data from AVHRR, and soil and daily meteorological data, net primary productivity maps over
the BOREAS region and Canada are produced at 1 km resolution. |