BROMINE MONOXIDE SENSOR
The instrument consists of two portions: 1) the scan head, which resides above the ice to receive skylight, and 2) the computer/spectrometer, which resides deep below the ice for better temperature stability. The scan head orients a telescope to scan the sky for halogen gases and couples this skylight into a fiber optic that then brings the light below the ice for spectral analysis. The computer/spectrometer module consists of a low-power single-board computer, motor driver, interface electronics, and a miniature CCD-based spectrometer.
The raw data from the instrument are scattered skylight spectra. These data are then processed in our laboratory to produce a timeseries of halogen gas abundances and other data products. A sample of data from a similar instrument in 2005 is shown in the figure. In the top panel is ozone, measured with an instrument similar to the one that Professor Shepson’s group is using on the Obuoy. The middle top panel is BrO derived from MAXDOAS instruments. The lower two panels represent airmass histories. The lower middle panel is the contact with first year ice, and the lower panel is the contact with potential frost flowers (PFF). See Simpson et al.,  for details.