Rosalind E. Rickaby

2010 James B. Macelwane Medal Winner

David B. Lobell, Rosalind E. Rickaby, and Jasper A. Vrugt were awarded the 2010 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 15 December 2010 in San Francisco, Calif. The medal is for “significant contributions to the geophysical sciences by an outstanding young scientist.”


It is an honor and a great personal pleasure to introduce Rosalind E. Rickaby of Oxford University, recipient of the 2010 AGU James B. Macelwane Medal. Ros has made insightful contributions to the paleoceanography of the glacial and interglacial oceans. She has developed expertise and has applied her insights into marine geochemistry to the study of past oceans, and she has advanced understanding of the physiological and biochemical processes that govern the behavior of key paleotracers. Ros was an undergraduate at Cambridge University and stayed on for her graduate research under my supervision. Her thesis work focused on using trace element incorporation in planktonic foraminifera to assess glacial—interglacial changes in the productivity of the Southern Ocean. Following her Ph.D., Ros moved to the other Cambridge for a postdoc at Harvard with Dan Schrag, and coincidentally encountered Edouard Bard on sabbatical at that time, before she moved to Oxford. In her papers she has shown that the strontium/calcium ratio in coccoliths varies with 400,000-year-long cycles of carbonate accumulation in a way that points to clear secular variations in the rate of continental weathering. She has exploited cadmium/­calcium ratios in foraminiferal tests from intermediate—depth cores in the North Atlantic, providing a strong constraint on the mechanism that brought the Earth’s climate out of the last ice age. In a recent paper she showed that the ocean’s deep water was significantly more alkaline during each of the cold glacial stages of the past 800,000 years. This provides a very strong constraint on the mechanism that made atmospheric carbon dioxide (CO2) fall as the Earth’s climate headed into an ice age and then made atmospheric COsub>2 rise on the way out.

The key to her scientific contribution is that she is bringing into the field of paleoceanography an increasingly sophisticated understanding of cellular processes, both physiological and biochemical, that govern the behavior of paleoproxies. At the same time, she can recognize the important questions about past climate and is applying paleochemistry to their understanding in very successful ways. She is extremely creative and can leap from thinking about mechanisms of pelagic calcification to discussing the long-term evolution of ocean chemistry and its impact on climate. She has the combination of curiosity and intellect, which is rare. Notable among her honors are the European Geosciences Union Outstanding Young Scientist Award and the Philip Leverhulme Prize in 2008, and the Rosenstiel Award from the University of Miami in 2009. It is very fitting that the Macelwane Medal has been added to this list. Her superb record of research has already produced several important results. Even more exciting is the work that lies ahead.

—HARRY ELDERFIELD, University of Cambridge, Cambridge, UK


Thank you, Harry, for all your kind words, unwavering support, and gentle persuasion since the very start of my scientific career. I never thought I was good enough to “make it” as a scientist, and while always tantalized by the freedom and imagination of an academic career, I suffered a rather stuttering and indecisive start. My final Ph.D. year was a pivotal point. Weekly Eagle sessions with Tom Rowland, Carrie Lear, Paul Wilson, Ian Hall, and Mark Rudnicki released some steam, but I shall never forget those afternoons exploring the cunningness of cadmium in carbonates and the Southern Ocean, while also losing the (kaleidagraph!) plot in your office. That intellectual challenge, fun, and exploration got me hooked on all questions COsub>2 and on your belief in me. I cannot thank you enough, Harry.

Your quiet approach, though, did not prepare me for the scientific tennis I encountered with Dan Schrag at Harvard as a postdoc, and the constant barrage of thought aces fired at me. I thank Dan for his support and his infectious enthusiasm and curiosity to explore any aspect of the Earth system without constraint. Dan was also kind enough to introduce me to Francois Morel and Paul Falkowski, both of whom really influenced my interest in the crossover between biology and geology, a major thread of my current research. It was also at Harvard that I encountered Edouard Bard, on sabbatical from Provence. Edouard never stops thinking about science, which is inspiration itself. Thanks also to the 6 Marie Ave crowd, who richly enhanced my snow-filled Boston days and convinced me it definitely was not diagenesis.

Somehow, I then landed a “dream job” at Oxford. I thank Gideon Henderson for suggesting I apply, and I thank the faculty for taking the leap of faith to appoint me and being fantastic intellectual sounding boards. Special thanks have to go to Sam Shaw, Conall MacNiocaill, Al Woolway, Tamsin Mather, and Helen Johnson for adding the laughs; to Philip England, an incredible mentor; and to Bob Williams for teaching me about enzymes, metals, and life. I am gradually building a research group, and I want to thank all the outstanding past and present OceanBuggers for their stimulation and for indulging my disorganization and penchant for pain aux raisins! I have been lucky enough to encounter too many phenomenal scientists to name, but I am grateful to Wally Broecker, Ed Boyle, Kate Freeman, Peter Swart, Danny Sigman, Robbie Toggweiler, John Anderson, Jelle Bijma, Gerald Ganssen, Brad Opdyke, Judy McKenzie, Hilary Kennedy, Richard Zeebe, and Tom Marchitto, all of whom have tolerated my interminable questions and allowed me time for discussion.

I am over the Moon and gobsmacked by this honor. Thanks must go to my family, who stuck with me through the ups and downs, of roller coaster proportions; to my furry friend Maxwell; and to my earthmover Big Will. I am indebted to all of my letter writers and to the committee that decided to award this medal to me. I cannot believe that my name could join this list of such prestigious scientists. Being awarded this medal suggests that some, way more qualified than me, found seeds of potential in some of my work. My awesome task now is to try and fulfill their expectations.

—ROSALIND RICKABY, Department of Earth Sciences, University of Oxford, Oxford, UK