ASCOS was an interdisciplinary expedition to the central Arctic on the icebreaker Oden from 1 August to 9 September 2008. The expedition focused on processes relating to cloud formation in the summer Arctic and included observations of marine biology and chemistry, atmospheric chemistry, physical oceanography, aerosol chemistry and physics, and meteorology. OOTI instrument package is designed ... for in-situ measurement of ground level ozone and Gaseous elemental mercury, Bromine monoxide, ambient temperature and few quality control parameters over the ice by the ice breaker Oden on its ASCOS expedition. The package is battery powered and its operation was fully automated. OOTI was taken out on the ice for sampling different environmental conditions described into the ASCOS-OOTI-log file. DOAS scan head was installed on 50 cm platform. MAXDOAS instrument sampling rate was between 5 and 15 minutes depending on the light conditions. Multi-Axes Differential Optical
Absorption Spectrometer build by University of Heidelberg, Germany around Ocean Optics USB 2000 spectrometer was used to record solar spectra at elevation angles of 0, 2, 5, 10 and 20 degrees. Data collected were investigated for BrO, oxygen dimer O4, NO2 and HCHO trace concentrations. Results are included in ASCOS-OOTI-DOASBrO01.cvs file. The first column contains elevation angle of the instrument telescope (0 means horizontal position; the second Solar Zenith Angle, the third one is Date (DD/MM/YYYY). UTC time of the beginning of measurement interval (up to 15 minutes) as HH:MM:SS is included in the forth column; the fifth column contains RMS error of the simulated result with respect to the original spectra; the sixth one Differential Slant Column Density of BrO (molecules per square cm) with respect of each elevation cycle zenith measurement; Differential Slant Column Density of oxygen dimer O4 (molecules per square cm). NO2 and HCHO concentrations were bellow the de
tection limit during the sampling campaign.