Aerosol chemical composition (major ions and iodine speciation) during the TransBrom cruise in the western Pacific Ocean, October 2009

Size segregated aerosol samples were collected during the Very short lived bromine compounds in the ocean and their transport pathways into the stratosphere (TransBrom) cruise (FS Sonne, SO202) during 9 - 25 October 2009 in the western Pacific Ocean (~141 E - 146 E, 20 S – 43 N). The samples were collected by Christian Müller, Sebastian Wache and Arne Lanatowitz of GEOMAR, Kiel, Germany. The aerosol sampler was situated on the roof of the ship's wheelhouse. 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 the samples varied between 20.3 and 26.8 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. The dataset contains the atmospheric concentrations of all measured soluble major ions (in nmol/m³) and iodine species (in pmol/m³).