MAX-DOAS measurements were performed during the cruise leg MSM 18/3 using the same MAX-DOAS instrument as during TransBrom described in Grossmann et al 2013 (doi:10.5194/acp-13-3363-2013). Except for the use of an updated water vapour cross-section (HITEMP) and the correction for vibrational Raman scattering in air (Lampel et al 2015, doi:10.5194/amtd-8-5895-2015), the fit settings also agree with Grossmann et al 2013 (doi:10.5194/acp-13-3363-2013). Aerosol profiles were retrieved using the O4 absorption at 360 nm using an optimal estimation scheme described in Yilmaz 2013 (http://archiv.ub.uni-heidelberg.de/volltextserver/13128/) and Frieß et al 2006 (doi: 10.1029/2005JD006618) based on SCIATRAN (Rozanov et al 2010, doi:10.1016/j.asr.2005.03.012). These aerosol profiles were used as input parameter to calculate IO concentration profiles during the cruise leg MSM18/3. Here the surface volume mixing ratios are shown.Upper Limits were determined for the following species, which were not detected in significant amounts during the cruise:BrO: 2.2e13 molec/cm2 at a telescope elevation angle of 3°, which corresponds to an average surface volume mixing of 1.5±0.5 ppt. The spectral settings for the BrO retrieval, which were applied here are in agreement with Pinardi et al 2013 (doi:10.5194/amt-6-167-2013).Glyoxal: 5e14 molec/cm2 at a telescope elevation angle of 3°, which corresponds to an average surface volume mixing of 25±10 ppt. The fit range was 432-460 nm and otherwise agreed with the spectral analysis of Glyoxal during Polarstern ANT28 listed in Mahajan et al 2014 (doi:10.1002/2013JD021388).Formaldehyde mixing ratios can be processed on request. The spectral data of the measurements is stored on the measurement data server of the Institute for Environmental Physics, University of Heidelberg.