Global Wetland Monitoring with AMSR-E Passive Microwave Radiometry

Methane is the most potent green house gas in Earth's atmosphere. Recent findings have raised wide concern as to whether living plants have a significant role in producing large amounts of methane. Although such findings may contradict the common understanding of many atmospheric scientists, laboratory studies have demonstrated that it is not clear how accurately natural methane production can be measured. Our study investigates the impact of natural wetlands on variations in methane out-gassing within a global modeling construct. At a first step, we utilize newly available passive microwave measurements from the AMSR-E radiometer to observe Earth's largest wetland regions and to monitor their seasonal behavior. A remote sensing technique is presented that exploits the temporal variability of daily AMSR-E brightness temperature observations to detect changes in water distribution that control inundation patterns for large wetlands in Siberia, North America, and the Amazon Basin susceptible to strong seasonal shifts in surface water retention or precipitation amounts. Initial results demonstrate that our method can be applied directly and without any tuning applied to the input remote sensing signal, though careful evaluation of our product with in-situ information remains to be carried out. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.