Peak sighted during an ice coring reconnaissance, western Tibet, August, 2004. Photo: Ryan Vachon.
Research
The INSTAAR Stable Isotope Lab is a focal point of interdisciplinary research programs partnering 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 throughout the global environment.
- Carbon cycle and green house gases
- Paleoclimate from ice cores
- Hydrologic cycle
- Ecological studies
Overview
Since 1989 INSTAAR SIL has used stable isotopes to address two major research areas: the carbon cycle through carbon and oxygen isotopes in atmospheric CO2, and paleoclimate reconstructions through oxygen and hydrogen isotopes in ice polar cores. Since then, we have added the capacity to analyze carbon and hydrogen isotopes in atmospheric methane, and carbon in organic matter, using EA-MS technology.
Carbon cycle and greenhouse gases
By studying the isotopes of atmospheric greenhouse gases, we are helping to decipher the global sources and sinks of these gases and the carbon cycle.
Greenhouse gases act like a protective layer around the earth keeping necessary heat in. These gases include carbon dioxide, methane, water vapor, nitrous oxide, and carbon monoxide, to name a few. They allow short wave energy from the sun to reach the earth, and inhibit long wave energy (heat) from escaping the earth?s atmosphere back into space.
Although these gases are necessary for keeping the earth from freezing, the concentrations of these gases are increasing from a variety of sources, and play a major role in the energy balance of the earth. The measurements of isotopes, along with concentrations, of greenhouse gases in our atmosphere are crucial to our understanding of their global distribution, their sources and sinks. Global climate computer models are constrained by these data, giving us a better understanding of global climate change and increase their predictive capability for making policy decisions for our global future.
SIL Role
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 flask pairs sampled weekly from over 55 sites from the NOAA Cooperative Sampling Network (see map below). We are currently working on being able to analyze deuterium of methane and are looking at developing a method for analyzing C13 and O18 of carbon monoxide.
See NOAA ERL links at right for more...
Ice Cores
Ice cores are one of the world's richest paleoclimate archives, unique for their combination of high resolution and long time scales.
Future climate changes large enough to disrupt the worlds economy and health are difficult to predict. Improved predictions require examining how earths climate has changed in the past. Ice cores are a rich archive of past climate change that we have only begun to explore.
SIL Role
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, ISIL has become a world leader in measurement of both deuterium/hydrogen and oxygen-18/16 ratios of ice.
Biogeochemical Cycling
Stable Isotopes in the biosphere
SIL Role
One of the more recent additions to SIL has been the coupling of a Thermoquest Elemental Analyzer 1110 with a SIRA Series II mass spectrometer to give us the capability to analyze organic materials for c13 isotopes. This has been quickly followed by a strong demand from our biogeochemical collaborators for running organic leaf matter and soils. We have so far run over 1,000 samples in this manner so far. This analysis capability opens the door for a great many studies that are critical to further understanding the coupling between the biosphere and the hydrosphere.
In addition to lab work, our research provides exciting field opportunities to students and other members of the lab.
Water Cycle
Isotopes in Precipitation.
SIL Role
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. Stable Isotopes are a unique tracer that can reveal volumes about the origin and distribution of precipitation on our planet. Linking and comparing modern day precipitation patters to those recorded in ancient ice cores gives insight into broader scale climate change.
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.