Swenson Receives 2011 Geodesy Section Award

Sean Claude Swenson received the 2011 Geodesy Section Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award is given in recognition of major advances in geodesy.


swenson_seanWe are delighted to see Sean Swenson receive the 2011 Geodesy Section Award. Sean is a superb young scientist who, through his ideas and publications, has had a significant impact on the Gravity Recovery and Climate Experiment (GRACE) satellite mission. He has fundamentally advanced the way people analyze and interpret GRACE data. His work has involved both the development of analysis techniques and the application of those techniques to geophysical problems.

Sean’s contributions to GRACE analysis include the development of methods for transforming the GRACE spherical harmonic gravity coefficients into regional estimates of surface mass and his discovery of a way to clean up much of the short-scale noise in the publicly available GRACE data. Both of these techniques are straightforward to implement and are now routinely applied by users everywhere.

But Sean’s work extends well beyond the development of analysis methods. His reason for working on analysis procedures was his desire to extract small, localized signals from GRACE data to study geophysical problems. He has used GRACE to study such varied things as the mixed-layer depth of the Caspian Sea; the vertical and horizontal scales of soil moisture in various regions of North America; the source of lake level fluctuations in Lake Victoria; regional-​scale fluxes of atmospheric water vapor; and the reliability of the large-scale, high-latitude winter precipitation data sets routinely used to force climate models.

Sean’s work has been extremely influential, especially for somebody so early in his career. He is an innovative, rigorous, enthusiastic, and highly unassuming young scientist who is an outstanding choice for the Geodesy Section Award.


John Wahr, Department of Physics and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder
Mark Tamisiea, National Oceanography Centre, Liverpool, UK


I am honored to receive the AGU Geodesy Section Award; it is certainly a pleasant surprise. My contributions to geodesy derive from my involvement with the Gravity Recovery and Climate Experiment (GRACE), which has been to me and many others a tremendous source of information and opportunity. The scope of geophysical phenomena that can be addressed by GRACE is extensive, including glacial ice loss, land-ocean water exchange, groundwater depletion, and surface water management to name but a few.

For the past 10 or more years the GRACE mission has enabled me to explore a wide variety of topics in the Earth sciences, from spectral analysis and filtering techniques to hydrological modeling. While GRACE has already helped quantify the role of terrestrial water storage in the water cycle, many questions remain. Some will be answered by longer data records, some by ­higher-​­accuracy future GRACE-type missions, and some by novel applications of current data.

I am eager to see what new insights the GRACE community will obtain in the future, and I hope to remain an active participant in those endeavors.

We are all born ignorant and spend the rest of our lives hopefully becoming less so. I would like to thank those who have helped my slow progress down that path. There are many colleagues in the geodetic community and collaborators in other fields whose interactions have benefited me, but I would especially like to thank Mark Tamisiea and Isabella Velicogna for their constant encouragement and, most of all, John Wahr, from whom I continue to learn what it means to be a good scientist.

Sean Claude Swenson, National Center for Atmospheric Research, Boulder, Colo.