Creativity Prize (Co-Winners)


ZredaDesiletsThe team of Dr. Marek Zreda (University of Arizona) and Dr. Darin Desilets (Sandia National Laboratory, USA).
They are being awarded for their groundbreaking work with the Cosmic Ray Probe, a technology which uses cosmic-ray neutrons to measure soil moisture content and snow pack thickness over an area of tens of hectares — passively, non-invasively and economically.

These measurements provide hydrologists and atmospheric scientists with an entirely new perspective on water near the interface between the ground and the atmosphere, as well as giving water managers, engineers and agriculturalists an invaluable but economical new tool to monitor a critical part of the hydrologic cycle.

soil-waterUntil now, techniques for measuring soil water content and snow pack have operated at the point scale (e.g. invasive probes inserted into soil or snow) or at the kilometer scale (e.g. satellite and airborne remote sensing images). However, many hydrologic processes operate at a scale of tens to hundreds of meters - and it is this critical "blind spot" that the Cosmic Ray Probe reveals.

This new technology can be employed in water supply forecasting and promises to improve the utilization of irrigation water and should have its greatest impact in water scarce regions.

The probe can also be used for predictive weather and climate models by measuring soil water condition, since soil water content is currently a major source of uncertainty in weather and climate forecasts, due largely to a lack of suitable observations.

Winner Profile

Dr. Marek Zreda

Dr. Marek Zreda is Associate Professor of Hydrology, Department of Hydrology & Water Resources and Associate Professor of Geology, Department of Geosciences, at the University of Arizona, Tucson.


• Ph.D., Geoscience/Hydrology, 1994, New Mexico Institute of Mining and Technology
Dissertation topic: Development of the Cosmogenic 36Cl Surface Exposure Dating Method and its Application to the Chronology of Late Quaternary Glaciations.

• MS, Hydrology, 1990, New Mexico Institute of Mining and Technology
Thesis topic: Cosmogenic 36Cl Dating of Geomorphic Surfaces.

• BS (equivalent), Geology (Stratigraphy and Exploration), 1986, University of Warsaw, Poland.

Selected Awards:

• Packard Fellowship in Science and Engineering, 1995 - 2000.
• Hantush Fellowship, 1993, Hydrology Program, New Mexico Institute of Mining and Technology.


Dr. Darin Desilets

Dr. Darin Desilets is a hydrologist and geologist with specialties in isotope hydrology, geochronology and cosmicray physics. For the past three years he has worked as a research fellow at Sandia National Laboratories where he has turned his attention to hydrologic applications of naturally occurring radiation.


• Ph.D., University of Arizona, Tucson, AZ, Department of Hydrology and Water Resources, 2005.
Dissertation: Cosmogenic nuclides as a surface exposure dating tool: Improved altitude/ latitude scaling factors for production rates;

• M.S., University of Arizona, Tucson, AZ, Department of Hydrology and Water Resources, 2001.
Thesis: The global distribution of cosmic-ray intensity and applications to cosmogenic dating;

Selected Awards:

• Truman Fellow

Acceptance Speech

 desiletsspeechDr. Darin Desilets:

Marek Zreda and I are deeply honored to be here today to accept the 4th biennial Prince Sultan bin Abdulaziz Creativity prize. To share this award with such distinguished colleagues as Ignacio Rodriguez-Iturbe and Andreas Rinaldo only adds to the significance of this achievement. We congratulate our co-recipients on their accomplishments in Ecohydrology and wish them continued success.

Soil moisture is a critical variable from a number of perspectives, including plant growth, the carbon cycle, runoff forecasting, and numerical weather and climate modeling. It can make the difference between flood and drought.

While there has been substantial progress in remote sensing of soil moisture and in the fine-tuning of point-scale sensors, despite decades of research there has been little progress on methods that average over the scale of a small water shed, model grid or center-pivot irrigated field. However, research over the past has shown that better land-surface observations are sorely needed at this intermediate scale to fill the gap between global and point scales.

Marek and I have dedicated the past decade to this pursuit of a near-field remote sensing technique. If only we had known that from the beginning! Our initial work was centered on isotope geochemistry to support surface exposure dating in the field of geology. However, our study of the production rates of chlorine-36, which is produced in neutron interactions, led us to closely examine the behavior of neutron fluxes near the land surface. That work led to the surprisingly successful utilization of ambient neutron fluxes as a proxy for soil moisture. Cross disciplinary work naturally leads to new and exciting discoveries.

We can't help but think that future technical advances in the field of hydrology will continue to come at the interface of disciplines in the physical and natural sciences. We are fortunate enough that our sponsors at the US National Science Foundation, Sandia National Laboratories and the David and Lucile Packard Foundation have shared this view. We obviously owe much our success to individuals at these institutions that have supported us along the way.

Nevertheless, given the importance of water today, breakthrough discoveries in the field of hydrology are surprisingly rare. They need to be encouraged.

It strikes us that the Prince Sultan Bin Abdulaziz Creativity Prize is the only award in the field of hydrology that so explicitly seeks to recognize and roles of creativity, discovery and innovation as driving forces in water research. The prize is therefore a unique and much needed contribution to the field of hydrology. It is a noble effort.

We are proud to accept this award.

Winning Work

Zreda, M., D. Desilets, et al. (2008). “Measuring soil moisture content non-invasively at intermediate spatial scale using cosmic-ray neutrons.” Geophysical Research Letters 35. [The journal is published by the American Geophysical Union, USA.]

Desilets, D., M. Zreda, et al. (2006). “Extended scaling factors for in situ cosmogenic nuclides: New measurements at low latitude.” Earth and Planetary Science Letters 246: p. 265-276. [The journal is published by Elsevier Science B.V., The Netherlands.]

Desilets, D., M. Zreda, et al. (2007). “Scientist water equivalent measured with cosmic rays at 2006 AGU Fall Meeting.” Eos 88: p. 521-522. [The journal is published by the American Geophysical Union, USA.]

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