So do clouds. To determine how much sunlight is being absorbed, NTSG adds daily surface weather data from NASA's Data Assimilation Office to its own data. By isolating the cloud-free pixels from each orbit, NTSG algorithms piece together an artificially cloudless image, or at least an image as free from clouds as possible. NTSG uses this data to calculate a refined measurement of photosynthesis. These products are available to land managers responsible for government-owned land, including the Forest Service, the Bureau of Land Management, and national parks.
Private landowners are also welcome to use the products.
Running estimates that will take three to five years, but he's glad to see the process has started. If vegetation is beginning to decline, due to land use, pollution, climate, or anything else, we want to quantify where the change is occurring and how fast it's occurring. This may be the most important early warning sign. A global terrestrial monitoring network integrating tower fluxes, flask sampling, ecosystem modeling and EOS satellite data.