Stable Isotope Laboratory


The INSTAAR Stable Isotope Lab is a focal point of interdisciplinary research programs: we partner with a global array of researchers from a variety of academic institutions and governmental agencies. Isotopes provide a unique tool because they indicate, record, integrate, and trace processes in the global environment.

Our research includes

Carbon Cycle and Greenhouse Gases

We measure the stable isotopes of carbon dioxide and methane in order to decipher global sources and sinks of these greenhouse gases.

Clouds drifting past Denali.

As the concentrations of greenhouse gases such as carbon dioxide and methane increase, the climate of the earth is changing. It is important to understand where the gases are coming from -- the sources (both man-made and natural)-- and where the gases go -- the sinks (ie., destruction of CH4 by other chemicals or CO2 uptake by plants). Stable isotopes are very useful for understanding sources and sinks due to processes that discriminate against one isotope over the other. The measurements of isotopes, along with concentrations of greenhouse gases in our atmosphere, constrain models of these gases and increase their predictive capability for understanding future climate regimes and making policy decisions.

The INSTAAR Stable Isotope Lab (SIL) has collaborated with the Carbon Cycle Greenhouse Gases Group (CCGG) at NOAA Environmental Research Laboratory Global Monitoring Division to measure C13 and O18 of carbon dioxide since 1990, and C13 of methane since 1998. This involves measuring flasks and programmable flask packages from the NOAA Cooperative Sampling Network (see map below). We are currently working on analysis of deuterium of methane and are developing a method for analyzing C13 and O18 of carbon monoxide.

See NOAA ESRL for more information, or go directly to the data. To learn about why isotopes are useful for understanding sources and sinks of carbon, click here.

Ice Cores

We measure the stable isotopes of oxygen and hydrogen in water from Ice cores. Ice cores are rich paleoclimate archives, unique for their combination of high resolution and long time scales.  Understanding the climates of the past is essential for predicting the Earth’s responses of human-caused climate change, and ice cores are invaluable in this effort.

NEEM camp. An international ice coring project. Photo by Tyler Jones.

For more than 15 years, SIL has been involved in ice core projects in Greenland, Antarctica, the high-altitude tropics (Ecuador, Peru, Tibet), and other regions. Over this time, SIL has become a world leader in measurement of both deuterium/hydrogen and oxygen-18/16 ratios of ice.

To see basics of ice core drilling, follow this link to the NEEM website.

Our current ice coring projects are at NEEM, in Greenland, and WAIS Divide, in Antarctica. We have just finished measuring the ice from WAIS Divide on a continuous melter system connected to a Picarro cavity ring-down mass spectrometer. This has allowed a higher-than ever measurement resolution.

Natural gas development impacts and best practices

The Mobile Methane Analyzer. Photo by Christi Turner.

SIL is participating in the CU-based, NSF funded Sustainability Research Network called the Air Water Gas project which is aimed at studying the oil and gas industry in the Rocky Mountain West  (  The mission of this project is to provide a logical, science-based framework for evaluating the environmental, economic, and social trade-offs between development of natural gas and protection of water and air resources. The project also aims to educate the public and influence the development of policies and regulations governing natural gas and oil development.

Unlike all of our lab-based measurements, Mobile Methane measurements are recorded on the fly as the vehicle drives. The data is plotted onto an interactive map and landsat image.

Visual display of a mobile methane sampling along roads in Weld County.

And more. ...

Stable Isotopes in the Biosphere

Denali National Park.

Carbon isotope ratios of organic material are useful tools in ecology and ecosystem science. We have measured thousands of leaf, soil, and other organic materials in studies aimed at understanding plant physiology, hydrology, and biogeochemistry.

Stable Isotopes in Precipitation

Mirror Lake.

The hydrologic cycle plays in important role in ice core research. Many of the discoveries made from polar ice cores have deepened our understanding of long term climate signals in both temperature and precipitation; likewise, understanding isotopes in precipitation today are essential to understanding the ice core record. Stable Isotopes are a unique tracer that can reveal volumes about the origin and distribution of precipitation on our planet.

The SIL has collaborated in a large scale effort of analyze the stable isotopes of archived samples obtained from the Global Network of Isotopes in Precipitation (GNIP) program. Students at CU have produced and analyzed seasonal patterns of isotopes in precipitation over the United States.


Contact Information

(Phone) 303 492-7985
1560 30th Street
Boulder, CO 80303