Monitoring the Earth's Climate Through Gravity: Latest Results from GRACE
Michael Watkins, Grace project scientist at JPL, Jet Propulsion Laboratory
The Gravity Recovery and Climate Experiment (GRACE), is a revolutionary satellite system that tracks large scale movements of mass, primarily water, in the Earth system through their gravitational effect on the satellite's orbital motion. These direct mass observations are complimentary to, and in cases have advantages over, many classes of altimetric and related remote sensing observations. Since launch in March 2002, GRACE has measured important trends in polar ice mass in Greenland and Antarctica, water storage variations in major river basins on multiple continents, and identified ocean bottom pressure variations in the Antarctic Circumpolar Current. In this talk, we will highlight the engineering design of the system that allows sub-micron distance measurement between the two spacecraft, review recent GRACE findings, and cutting edge GRACE analysis techniques. Finally, we will present the options for a follow-on mission, which could potentially involve sub-nanometer laser interferometry similar to the LISA mission.