Differential Optical Absorption Spectroscopy data acquired at Sabancaya Volcano (Peru) on 21 May 2016

On 21 May 2016, two Differential Optical Absorption Spectroscopy (DOAS) instruments were used to measure the radiance of scattered solar radiation passing through the plume emitted from Sabancaya Volcano, Peru. Spectra were recorded in the ultraviolet (UV: 280 425 nm) and visible (Vis: 450 780 nm) wavelength ranges at 0.6 and 1.2 nm resolution, respectively. Two distinct experiments were performed using different measurement geometries. In the first experiment, two zenith-looking telescopes were mounted on a vehicle, each coupling scattered sunlight into one of the two DOAS spectrometers. The vehicle traversed beneath Sabancayas volcanic plume between 16:43 to 17:39 UTC collecting 2075 UV spectra and an equal number of Vis spectra. In the second experiment, a scanner was used to scan the spectrometers viewing direction through the volcanic plume. The scanner was located at -15.824N, -71.843E and aimed at the north-eastern horizon. It scanned the spectrometers viewing direction from 4 to 82 degrees elevation in steps of 3 degrees. The plume was encountered at about 20 degrees elevation. The scanner was held at each position for about 5 seconds during which both UV and Vis spectra where acquired. The plume scans ran from 19:11 to 21:11 UTC and 702 spectra were recorded in both the UV and Vis spectral ranges. All recorded spectra were stamped with GPS time and location. Each spectrum is saved in a separate ASCII file which includes the 2048 radiances recorded across the spectral window of the respective spectrometer along with metadata associated with each acquisition.