Isotopic Measurements

The sources and sinks of various atmospheric constituents are important to quantify but difficult to measure. One approach to addressing this challenge is based on the measurement of the isotopic composition of atmospheric species. Because different sources tend to have distinct isotopic signatures, the measurement of concentrations or fluxes with isotopic resolution can highly constrain the potential sources and sinks. Aerodyne produces several instruments with isotopic measurement capability.

The Carbon Dioxide Isotope Monitor provides real-time measurement of the isotopic ratio of 13CO2 and CO18O in ambient air samples. Its precision is unrivalled among optical isotope monitors and approaches that of Isotope Ratio Mass Spectrometry – but with real time results even in a field setting.

Isotopic Monitors for CH4 and N2O are now available. These instruments are specialized versions of the Dual Laser instrument described above.  For methane, we measure the isotopic ratios of 13CH4 and CH3D. For, nitrous oxide, we report the isotopic ratios of 15N14NO, 14N15NO and 14N14N18O.