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.