ICOS

The Air Force Research Laboratory is seeking to understand the atmospheric interactions of 1um radiation propagation in the arctic environment. The aerosol constituents of arctic haze may produce increased scattering or absorption of this wavelength compared to other regions. Extinction measurements will be collected with a diagnostic based on the technique of off-axis integrated cavity output spectroscopy (ICOS), a variant of cavity ring-down spectroscopy. The sensitivity of ICOS, on the order of 1-2 Mm-1, provides the ability to detect aerosols without the need of a km test range required by other absorption technique. The commercial ICOS spectrometer, available from Nikira Labs, is fairly autonomous and can continually collect samples at a rate of 1Hz. An optical particle sizer (TSI 3330) will be paired with the device to measure particle size distribution, total particle concentration, and flow rate throughout the experiment. The data collected with these instruments, and when paired with available aethalometer data at the nearby NOAA facility, should provide better resolution of the absorption and scattering coefficients of the arctic haze, which can be used to increase the fidelity of climatological models.

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