The aerosol size distribution was measured with a custom made scanning mobility particle sizer (SMPS), range 18⁠ – ⁠660 nm. Aerosols are important for a variety of reasons, one of the most prominent is that a sub-set of the aerosol population can act as cloud condensation nuclei (CCN) influencing cloud formation and the Earth radiative budget. The measurements reported here can be used to investigate aerosol sources and processes. Moreover, an interstitial inlet was used to characterize the interstitial aerosol population during fog events. Measurements were performed on the 4th deck of icebreaker Oden during August and September 2018 along the track of the expedition. The concentration is reported as dN/dlog(Dp) per cubic centimeter with a 3 minutes time resolution.