BLAH BLAH, what do you we want here?

The objective of the research driving development of GLO-PEM is the ability to use remotely-sensed observations of surface spectral reflectance and thermal emission to model and monitor terrestrial net primary production and gross primary production at the global scale. Global data sets of such variables are being collected by the Oak Ridge DAAC for validation purposes. GLO-PEM is the first attempt to utilize the production efficiency concept globally, in which the canopy absorption of photosynthetically active radiation (APAR) is used with a conversion "efficiency" or carbon yield of APAR in terms of gross primary production (GPP). The GLO-PEM model is thus based on physiological principles, in particular the amount of carbon fixed per unit APAR is modeled rather than fitted using field observations. The approach is unique in that it uses satellite data to measure both APAR and the environmental variables that affect the utilization of APAR in primary production. The use of satellite measurements gives global, repetitive, spatially contiguous and time specific observations of actual (rather than potential) vegetation conditions. Because all the information is derived from satellite observations, the model is responsive to real events such as El Nino - Southern Oscillation (ENSO), volcanic eruptions and other forms of Global Environmental Change being studied as part of NASA's Mission to Planet Earth. The results of the modeling work show that there are significant possibilities of inferring biological and environmental variables using multispectral techniques that need to be explored if the new generation of satellite remote sensing systems is to be exploited productively.