Differential Optical Absorption Spectroscopy data acquired at Mount Pagan volcano (Mariana Islands) on 6 April 2014

On 6 April 2014, a Differential Optical Absorption Spectroscopy (DOAS) instrument was used to measure the radiance of scattered solar radiation passing through the plume emitted from Mount Pagan volcano, Mariana Islands. Spectra were recorded in the ultraviolet (UV: 240 – 390 nm) wavelength range at 0.6 nm resolution. A scanner was used to scan the spectrometer's viewing direction vertically through the volcanic plume. The scanner was located at 18.1235N, 145.7608E and aimed directly to the north (0 degrees azimuth). It scanned the spectrometer's viewing direction from 1 to 90 degrees elevation in steps of 1 degree. The plume was encountered at about 15 to 20 degrees elevation. The scanner was held at each position for about 1 second during which the UV spectrum was acquired. The plume scans ran from 08:22 to 09:14 local time and 2,203 spectra were recorded. 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 spectrometer along with metadata associated with each acquisition. A separate file named 'WavelengthCalibration.CSV' contains the spectrometer's wavelength calibration, where each pixel number is assigned a wavelength in nanometers.