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Isotopic analysis in global change • Carbon cycle • Instrument development

I manage the INSTAAR Stable Isotope Lab and use stable isotopes to study biogeochemical processes that control environmental change on human timescales.

Research interests: carbon cycle; paleoclimate records in ice cores; atmosphere-ice sheet interactions; water vapor isotopes in the atmosphere.

The Stable Isotope Lab collaborates with the NOAA Global Monitoring Division and measures stable isotopes of biweekly atmospheric trace gas samples from over 50 sites, adding to a 20+ year . The lab also creates extremely high-resolution paleoclimate records from stable isotopes of polar ice cores from and . With a fleet of 8 mass spectrometers and a growing number of laser-based spectroscopy instruments, the lab continues to pioneer new methods and techniques using stable isotopes for a variety of applications.

ÍÃ×ÓÏÈÉú´«Ã½ÎÄ»¯×÷Æ· the Stable Isotope Lab  News about Bruce 

Jim White and I began the Stable Isotope Lab at INSTAAR in 1989 with two mass spectrometers, focusing on ice cores and developing methods for measuring isotopes in atmospheric CO₂. The lab has now grown to include multiple instruments and multiple projects. I manage the lab with its current staff of five, plus graduate students, and collaborate with many researchers on a variety of projects.

Current efforts include a pioneering effort into the use of unmanned aerial vehicles (UAVs, or drones) for making measurements of atmospheric water vapor and stable isotopes. The findings will inform a better understanding of ice sheet-atmosphere interactions and implications for quantifying direct sublimation, which impact surface mass balance, and by extension, sea level rise. This deeper understanding of water vapor and post-depositional changes in isotopes of surface snow will also further illuminate our interpretation of isotopic signatures in ice cores.

In addition to carbon cycle relevant measurements of atmospheric greenhouse gases, my field research is closely linked to the laboratory analysis of stable isotopes in ice cores from polar regions. More recently we have been investigating the role of water vapor isotopes in the atmosphere above the Greenland Ice Sheet. This is important because not only does the atmosphere transfer climate information to the ice sheet via precipitation that eventually makes up the ice core record, but the ice sheet exchanges water vapor with the atmosphere between snow storms, and possibly during them.

To do this we have employed unmanned aerial vehicles (UAV's) or drones to collect air samples that we analyze. In 2018 we deployed a multi-rotor drone to prove the concept of remote sampling capability to ~500 meters above the ice sheet at the EGRIP Ice Core site in NE Greenland. In 2019 we used a fixed wing (3 meter wing span) UAV to collect samples 1,500 meters above the ice sheet, well into the planetary boundary layer. Results from these studies will deepen our understanding of the ice core record as well as shed light on direct sublimation of the ice sheet and the surface mass balance of Greenland.

Prior to INSTAAR, I was with the Water Resources Division of the USGS, Project office Glaciology. My passion for Earth science has always included an important role for field work. Sites over the years have included Greenland, Antarctica, Ecuador, Alaska, the Central Pacific islands, Grand Canyon, and the North Cascades.

Education

• MS: University of Colorado, 1994

Outreach

Publications

For additional publications, see .