Enhancing GRACE/GRACE Follow-on Products for Hydrological Applications

Matt Rodell
NASA Goddard Space Flight Center

The potential of GRACE and GRACE Follow-on missions to benefit hydrological research and water resources applications is enormous, because no other measurement method has ever provided global maps of the integrated quantity of water stored on and below the land surface. However, three factors have limited the acceptance of GRACE as a tool for such applications: (1) its spatial and temporal resolutions are low relative to other hydrological observing systems; (2) the current product latency greatly diminishes its value for operational applications; (3) total terrestrial water storage is a measurement unfamiliar to hydrologists used to dealing with discrete measurements of specific elements of the water cycle. These issues might be alleviated by hardware and processing improvements in a GRACE Follow-on mission, but they can also addressed using innovative methods such as data assimilation into a model which synthesizes observations of multiple variables from a variety of sources.