Christian Frankenberg

2014 James B. Macelwane Medal Winner

Rajdeep Dasgupta, Christian Frankenberg, J. Taylor Perron, David Lawrence Shuster, and Jessica Erin Tierney were awarded the 2014 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 17 December 2014 in San Francisco, Calif. The medal is for “significant contributions to the geophysical sciences by an outstanding early career scientist.”


Christian Frankenberg is pioneering the development and use of satellite remote sensing for new and original scientific research coupling ecology with the ­larger-​scale physical processes of the Earth system carbon and water cycles. He is one of the discoverers of the new remote sensing technique for solar-induced fluorescence that is providing new global data on the terrestrial biosphere. This is one of the most important discoveries in remote sensing in recent years.

He began his early research as an undergraduate and graduate student in Germany, moving from geoecology to remote sensing. He provided algorithms to derive atmospheric carbon monoxide and methane from Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) spectral observations and analyzed these data to estimate global emissions. When he moved to the Institute of Environmental Physics in Heidelberg and then the Netherlands Institute for Space Research in Utrecht, he continued developing new satellite data products, extending them to water vapor and the important isotopologue, HDO. His research on the fractionation of HDO provided new insights into the dynamical processes regulating water vapor in the lower troposphere and thus the global water cycle.

Currently at the Jet Propulsion Laboratory at the California Institute of Technology, Christian has been an integral part of the Orbiting Carbon Observatory 2 (OCO-2) team involved in the challenge of measuring atmospheric carbon dioxide concentrations from space with the sensitivity to infer patterns of the underlying exchange of carbon dioxide with the surface. In analyzing the Japa­nese Greenhouse Gases Observing Satellite (GOSAT) high spectral resolution data intended for greenhouse gas measurements, he and others discovered that the fluorescence photons emitted by chlorophyll during photosynthesis, even though small in number, could be detected as the filling in of the solar Fraunhofer lines. This unexpected by-product offers new information about global plant primary productivity, complementing existing light interception observations.

An impressive characteristic of Christian’s research is his ability to bring together an understanding of fundamental atmospheric radiative transfer, spectroscopy, and nuances of the performance characteristics of the instruments to first tease out these new data sets and then later to analyze them for new understanding of global biophysical processes. He has more than 64 peer-reviewed multidisciplinary publications to his credit since 2004, an impressive body of work that will no doubt continue to expand. These publications have already had both high impact factors as measured by their frequent citation and the more telling impact of stimulating new directions for satellite observations of the Earth system.

—Michael Gunson, California Institute of Technology, Pasadena, Calif.


Thank you, Mike, for your kind words, and thank you, AGU, the Macelwane committee, and my nominators, for this unexpected and overwhelming honor. Going through the list of previous recipients is stimulating and intimidating at the same time. I feel very lucky and honored.

Like life itself and the Earth system, careers are often nonlinear, and I am indebted to many scientists and friends who shaped mine. I was fortunate to start my Ph.D. work at the University of Heidelberg at a time when the ENVISAT satellite was just launched and the SCIAMACHY instrument started shaping my research path. After working with the inspirational Ulrich Platt at Heidelberg, I continued my research in Utrecht with a Veni postdoc fellowship and enjoyed working with a great group of scientists under Ilse Aben.

For various reasons, I may not have made the big jump across the pond to the Jet Propulsion Laboratory (JPL) but for my childhood friend Kai Buchholz. Working for the United Nations, he died tragically during the earthquake in Haiti, just when I started working for JPL in the United States. In many ways, he was the most extraordinary person I knew and has always been an inspiration and moral compass for me. I would not be standing here without him.

I came to JPL about half a year after the OCO launch failure, but we were lucky to be able to work with the Japanese GOSAT satellite and the National Institute for Environmental Studies and Japan Aerospace Exploration Agency teams. Kuze-san, Yokota-san, Dave Crisp, and Mike, thank you for all your support. Again, I was somewhat lucky and at the right place at the right time. Over the last few years, I drifted back to the roots by studying chlorophyll fluorescence from space. This not only was an exciting topic but also gave me the chance to meet and collaborate with great scientists, such as Joe Berry, who probably is one of the most original and knowledgeable yet humble scientists I know. Over the last few years I had the pleasure of working work with and being influenced by many others, including Chris O’Dell, Luis Guanter, Andre Butz, Joanna Joiner, and many others. I learned a lot from many more people than I could possibly mention here.

Last but not least, I want to thank my parents for providing me all the freedom I could wish for; my wife, Suniti, for all her support; and my son, Neal, for teaching me again how powerful curiosity is.

—Christian Frankenberg, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, Calif.