Field Worthy Sensor for Measurements of the Stable Isotope Ratio of CO2

Measurement of the ratio of the concentrations of the stable isotopologues of CO2 in the atmosphere can provide new understanding of the dynamics of CO2 exchange between the atmosphere and terrestrial ecosystems. On the local scale, such measurements enable the study of the net ecosystem exchange of CO2. On larger, continental-to-global scales, isotopically resolved concentration measurements of atmospheric CO2 are one means of monitoring the partitioning of CO2 between the major surface sinks represented by the oceans and the terrestrial biosphere. This project will develop instrumentation to enable routine, widespread measurements of these isotopes with good precision. Phase I will couple a near-IR tunable diode laser with a high sensitivity detection system and demonstrate the required measurement precision for monitoring the major stable isotopes of CO2. Phase II will design, fabricate, test, and field demonstrate a prototype field sensor for the major stable isotopes of CO2. Commercial Applications and other Benefits as described by the awardee The proposed compact and economical sensor for the stable isotopologues of CO2 should enable measurements of the net ecosystem exchange of carbon on a wider scale, with important implications for global climate change modeling and, ultimately, international energy policy.