Aerosol chemical composition (major ions and iodine species) in samples collected during the M138 cruise in the eastern Pacific Ocean, June 2017

Size segregated aerosol samples were collected during the M138 cruise (FS Meteor) during 6 June - 1 July 2017 in the eastern Pacific Ocean (~86 W - 76 W, 16 S – 5 N). The samples were collected by Hermann Bange of GEOMAR, Kiel, Germany. The aerosol sampler was situated on the roof of the ship's wheelhouse and its operation was controlled by an automatic wind sector controller to prevent contamination from the ship's stack. Samples were collected using a Sierra-type cascade impactor to separate the aerosol particles at an aerodynamic diameter cutoff of 1 µm. Collection time for these samples varied between 14.3 and 65.2 hours. Samples were extracted with ultrapure water and the major ions Na+, NH4+, Mg2+, K+, Ca2+, Cl-, NO3-, SO42-, oxalate, Br- and methanesulfonate were determined by ion chromatography (IC). Total soluble iodine (TSI) was determined by inductively coupled plasma - mass spectrometry (ICP-MS) and iodide (I-) and iodate (IO3-) were determined by IC-ICP-MS. Analysis work was performed by Andrew Smith of University of East Anglia, Norwich, UK. The dataset contains the atmospheric concentrations of all measured soluble major ions (in nmol/m³)) and iodine species (in in pmol/m³). The data are reported in “Soluble iodine speciation in marine aerosols across the Indian and Pacific Ocean basins”, E. Droste et al., Frontiers in Marine Science, in preparation, (2021).