Abstract:
AirMOSS was selected by NASA in 2010 as one of the first 5 Earth-Venture-Suborbital missions, with the goal of reducing the uncertainty of net ecosystem exchange (NEE) in north America through provision of high-resolution surface-to-depth profiles of soil moisture to land hydrology and ecosystem models. AirMOSS is accomplishing this goal by producing retrieved maps of so-called root zone soil moisture (RZSM) at approximately 100-m resolution for 9 biomes (10 sites) in north America, ranging from the boreal forests in Canada to the tropical rainforests in Costa Rica. RZSM has been hypothesized to account for 60% or more of the uncertainty in estimates of NEE. AirMOSS, currently in its final mission year, has acquired about 3 years of observations of RZSM at its study sites, with a total of 21 flight campaigns per year. Each flight campaign has included 2-3 flight dates. The RZSM maps have been retrieved from polarimetric synthetic aperture radar (SAR) instrument built by the Jet Propulsion Laboratory and flyign aboard a Gulfstream-3 airplane, operated by NASA Johnson Space Center. The estimation algorithms for deriving the RZSM maps have been matured throughout the mission, and have been shown to produce estimates of RZSM that are accurate to within 0.02-0.12 m3/m3 compared to in-situ validation data. The mission has also produced higher level RZSM products at hourly intervals, using land hydrology models, whose parameters are optimized using the AirMOSS snapshots. The ultimate product of the mission are the NEE estimates, generated not only for the mission study sites, but also upscaled to the entire scale of north America. These results are all under production, with the final mission products expected in May 2016. This presentation will give an overview of the mission, its products, and the main scientific findings. Several other papers in this session provide more details on each of the various aspects of the mission.