Guido Salvucci

2003 James B. Macelwane Medal Winner

Boston University

Guido D. Salvucci was awarded the Macelwane Medal at the AGU Fall Meeting Honors Ceremony, which was held on 10 December 2003, in San Francisco, California. The medal honors “significant contributions to the geophysical sciences by a young scientist of outstanding ability.”


“Guido Salvucci exemplifies the tenets of the AGU Macelwane Medal—recognition for exceptional contributions by a young scientist. He has made research contributions in diverse topics in hydrologic science, and he has opened up new frontiers several times in his young career.

“His signature is a deep and intuitive solution to unresolved problems that have been around in the discipline for decades. The solutions are invariably simple and free of obfuscation and jargon. They demonstrate an intuition for physical processes and a skill to extract just the right amount of analytics to make a contribution stay and speak to many.

“Guido has tackled some of the most fundamental problems in hydrologic science and provided breakthroughs where walls once stood. Especially noteworthy are his contributions to (1) understanding the significant role of climate, soils, and terrain in organizing the pattern of hydrologic exchanges; (2) understanding the effects of rate-limitation processes in soil physics; (3) unraveling the role of time perturbations and spatial scale in water balance; and (4) inferring land surface fluxes from remote sensing measurements.

“Early in his career Guido engaged an age-old problem in hydrology dealing with the spatial pattern of exchanges between surface water and groundwater systems. Guido developed and tested an innovative conceptual framework for characterizing these patterns that emerge from the interactions between terrain, surface flux to atmosphere, and subsurface flow.

“Another area of notable contributions by Guido is remote sensing of land surface fluxes, for example, evaporation. Evaporation, the core driver of linked water, energy, and biogeochemical cycles over land, is not monitored such to allow mapping. In a series of studies Guido offered a truly remarkable solution that is based on fundamental physics of the problem and does not rely on parametric assumptions. He shows that the transition from potential evaporation—limited by available energy—to reduced evaporation—limited by water in the root zone—is detectable from transitions in spectral reflectivity in the visible range and emission in the thermal range. He combines the knowledge of the transition timing derived from soil physics to show that the rate of evaporation in each regime is predictable. This is a remarkable achievement that again sets the standard for future contributions in this field.

“Guido has recently created new value for historical observations using remarkably clever conditional sampling. In this way he has managed to unravel the dependence of evaporation and recharge/discharge losses on soil moisture from measurements of precipitation. The solution is fundamentally independent of the scale of observation. The breakthrough allows the estimation of the state control on fluxes without any parameterization assumptions and using available measurements.

“Award of the Macelwane Medal is a recognition of Guido’s contributions and a recognition of the medal’s standards. Guido is a respected colleague who is known for his modesty and personal integrity. I have the added pleasure of witnessing Guido as a father, a husband, a son, and a friend, all of which he performs with exceptional virtue.

—DARA ENTEKHAB, Massachusetts Institute of Technology, Cambridge


“Thank you, Dara, for those kind words and for sharing your friendship with me for so long. And thank you to all of those who nominated me and to the selection committee that chose me to receive this medal. I hope I can live up to its expectations.

“There are many other people I want to thank tonight, all of whom have in some way helped me to be up here. Professionally, I want to thank a group of fantastic professors at NYU’s Department of Applied Science: Marty Hoffert, Mike Rampino, and Tyler Volk. I haven’t spoken to them in 14 years, but I want them to know that the Earth-systems program they taught was infectious. Were it not for their enthusiastic teaching, I would be a structural engineer today.

“At the Parsons Lab of MIT, I had the good fortune of working with Peter Eagleson and Dara Entekhabi, both of whom are deeply creative and critical thinkers. They exemplified mentorship by sharing their love of hydrology, giving me guidance when I needed it and freedom to explore ideas, all the while providing lots of professional encouragement and personal friendship. The faculty, staff, and students of the Parsons Lab have a special chemistry that I will remember fondly. Every once in a while I call Dara to see if he could use a somewhat older and perhaps overpaid research assistant.

“This was also when I met my wife, Amy, whose distracting charm almost got me kicked out of graduate school (I got a C in probability and statistics that semester). To make a long story short, Eagleson let me stay, and Amy became my best friend, strongest supporter, and the love of my life.

“At BU, I have been lucky to work with great graduate students and faculty in two diverse departments, Geography and Earth Sciences. Being the only hydrologist at BU could have been lonely. Instead it has provided me with close friends, great graduate students, and unexpected collaborations with time series econometricians, remote sensing scientists, and climatologists.

“Last but not least, my grandparents and parents provided me with a wonderful home, strong role models of unselfish hard work, and continuous love and support. And now seeing my own children grow and become curious about the world has been a thrill. Jack is curious about what the ‘dirt’ on the moon looks like, and Zoe has been making Venn diagrams about family food favorites! I think we might have two more AGU members in the family. They are both proud of me for winning this medal, and their pride is a source of joy.

“All of us here work in a field where we are constantly being reviewed, anonymously and critically, on each paper we write, class we teach, and idea we propose. As we all learn early on from our mentors, it is a field that requires thick skin. And for whatever reason, what typically sticks in one’s memory are the most recent review and the most critical one. This recognition, however, will always stay with me. Thank you for this honor.”

—GUIDO D. SALVUCCI, Boston University, Mass.