Instruments

Cavity ring down spectroscopy (CRDS) is a high sensitivity absorption technique that exploits an optical cavity, in this case, two high reflectivity mirrors aligned parallel to one another, to achieve optical paths up to 100 km in a 50 - 100 cm

The nighttime nitrogen oxides, NO3 and N2O5, are reactive species that drive atmospheric chemical transformations in the dark.  The nitrate radical, NO3, has strong visible absorption bands near 662 nm.  The combination of cavity ring

The combination of broadband light sources with the path length enhancement achievable with an optical cavity allows for spectrally resolved optical extinction.  Light emitting diodes (LEDs) are high power light sources with a bandwidth