Gabriel J. Bowen

2012 James B. Macelwane Medal Winner


Gabriel J. Bowen was awarded the 2012 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The medal is for “significant contributions to the geophysical sciences by an outstanding young scientist.”


It is my honor to introduce Gabriel Bowen, a recipient of the 2012 James B. Macelwane Medal.  Gabe is a talented geochemist and geologist who is being recognized for his prolific contributions across a broad range of disciplines including hydrology, ecology, biogeochemistry, forensic anthropology, and paleoclimatology.  His primary contributions to these disciplines have come largely through the creative use of stable isotope tracers in combination with numerical modeling.


Gabe’s potential was evident from an early stage.  As an undergraduate at the University of Michigan under the tutelage of Bruce Wilkinson and K. C. Lohmann, he developed a statistical model to produce the first detailed map of the oxygen isotopic composition of precipitation on a global scale.  This initial experience set Gabe on a career path that would soon lead him to the forefront of Earth sciences, tackling questions on the dynamics of Earth’s climate, geochemical cycles, and biosphere, both past and present. His first stop was the University of California, Santa Cruz, where with Paul Koch and myself, he took on one of the more prominent questions of the time, how transient global warming at the Paleocene-Eocene boundary contributed to the major radiation of land mammals.  His research, which involved three years of challenging field sampling and lab work, ultimately proved that the earliest ancestors of several major modern orders of mammals originated in Asia.  It was at this time that Gabe’s full range of talents became apparent. Because this work hinged largely on carbon isotope stratigraphy, with minimal guidance, he modified a version of the Walker-Kasting carbon cycle model to quantitatively assess how in a rapidly warming climate, changes in plant and soil respiration rates influence the fractionation of carbon isotopes between the atmosphere and continental carbon reservoirs.


For his postdoctoral research, Gabe moved on to Utah where he, along with James Ehleringer and others, began pioneering work to solidify the foundation for applying the spatiotemporal isotope patterns in meteoric water to a broad scope of questions. This included expansion of the existing precipitation database through the clever use of substitute tap and ground water samples, and the initial development of integrated isomapping tools.  Gabe understood how such a well-documented and accessible database could be used to advance many disciplines, and took the lead in a community effort to develop the online application “Isoscapes.”   Utilizing this capability, he and his colleagues performed a comprehensive analysis, which verified the influence of temperature and precipitation intensity on the seasonal patterns in isotopes within specific geographic zones. This was a significant advance in applying proxy isotope records to reconstruct past variations in seasonality.  Gabe also contributed to the design of a strategy utilizing O and D/H isotopes as a means of determining origin and migration of animals.


In this era of specialization, Gabe is among a select group of talented young scientists who possess the creativity, breadth and skills to tackle a wide range of interdisciplinary problems. He is a reminder of how a broad foundation in Earth sciences can facilitate solutions to some of the more challenging problems of our time.


–James Zachos, University of California, Santa Cruz, California


Thank you, Jim, and thank you to AGU for this recognition and encouragement.  In reality, this award recognizes many who have shared their knowledge, guidance, and example throughout the years.

Growing up in Michigan’s Upper Peninsula, I was surrounded by great Earth science from glacially-polished Keweenawan basalts to invasive lamprey in Lake Superior.  Thank you first and foremost to my parents, Stephen and Nancy Bowen, for braving many long winters and giving me the opportunity to explore and question this unique environment.  My initial development as an Earth scientist was fostered by a long list of mentors at the University of Michigan.  Bruce Wilkinson taught me how important it is to ask the right questions.  K. C. Lohmann introduced me to stable isotopes.  Gregg Gunnell, Bill Bartels, Jon Bloch, and Phil Gingerich took me to the field and got me thinking about relationships between life and environment in geologic time.  Lynn Walter answered a random knock on her door one afternoon and put me to work in her lab, where I saw collaborative research in action.

The best tip I received at Michigan was about a small public university in the Pacific coast town of Santa Cruz and a professor there named Paul Koch.  Paul was and is a role model, an amazing scientist and person who can always distill the essence of a problem and always makes science fun.  Working with Paul and Jim Zachos on global change at the Paleocene-Eocene boundary introduced me to a vibrant community of thinkers; interactions with Gerry Dickens, Lee Kump, Richard Zeebe, and many others during this time helped me scale my biogeochemical thinking to a global scale.  A strong cohort at UCSC helped me find my way through graduate school.  Many of these individuals I’m lucky to still count as friends and colleagues.  Chief among them is my wife Brenda, who is an inspiration to me daily and who, along with our boys Isaac and Benjamin, makes every day a good day.

Following Brenda to the University of Utah in 2004 turned out to be another life- and career-defining experience.  There I had the privilege to work closely with Jim Ehleringer and Thure Cerling, launching lasting collaborations and developing new awareness of the broader relevance of our work.  During this time discussions with Jason West and others led to the elucidation of the isoscapes concept and development of a research community focused on this theme.  Over the subsequent years I have been privileged to work with an enthusiastic and supportive group of colleagues, first at Purdue University, where with Tim Filley and Greg Michalski I learned how to run a lab and a research group, and now at the University of Utah.

We live in a time when understanding our Earth could not be more important.  If every budding Earth scientist experienced the level of support and inspiration I have received from mentors, colleagues, collaborators, and students, those named here and many others, our field and our society would be greatly advanced.  May we strive to make it so!

–Gabriel J. Bowen, University of Utah, Salt Lake City, Utah