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).
Sampler Flow: 1 m³/minSubstrate Type: Whatman 41 celluloseSubstrate Pretreat: Washed in ultrapure water and then ashed at 450C for 4 hoursSize Seg Method: Sierra type cascade impactor. For most samples stages 3 and 4 were used and combined during analysis to give a fraction with aerodynamic diameter > 1 µm (Size_fraction coarse). Backup filter collected the < 1µm fraction (Size_fraction w). Method Publication: Yodle and Baker, Atmospheric Environment X, 1, 100009, (2019)DL Value: Where the detection limit applies, concentrations are quoted as less than the limit of detection; Example atmospheric detection limits (given in Comment below) have been calculated from analytical detection limits for an air volume of 2100 m³.
