Dataset: Total aerosol trace elements from bulk aerosol samples collected on Leg 1 (Seattle, WA to Hilo, HI) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1814) on R/V Roger Revelle from September to October 2018

A total of 12 48-hour integrated aerosol samples were collected during Leg 1 of the US GEOTRACES Pacific Meridional Transect research cruise (GP15), which took place on the R/V Revelle (cruise RR1814) during September-October 2018. The cruise track consisted of a southward transect across the North Pacific Ocean originating off of Alaska and terminating at Hawaii.

Bulk aerosol samples for multiple trace element analyses were collected using one of five Tisch Environmental high-volume (~1 m³ air min⁻¹) aerosol samplers (model 5170V-BL). For each deployment, 12 replicate 47 mm diameter Whatman 41 filters were loaded on open-face filter holders (Advantec MFS) installed on the aerosol sampler on a PVC adaptor plate (Shelley et al., 2015). Filters were acid-washed before use to reduce trace element blanks, following the procedure described by Morton et al. (2013). The samplers were deployed on the forward rail of the ship's 03 deck approximately 16m above sea level, to minimize the influence of sea spray on samples. Samplers were controlled by wind speed and direction, through a Campbell Scientific CR800 data-logger interfaced with an anemometer and wind vane set up in close proximity to the samplers, in order to eliminate contamination from the ship's stack exhaust. This setup was used to restrict sampling to periods when relative wind speed and direction were >0.5 m s⁻¹ and from within ±60° of the bow of the ship, respectively, for at least five continuous minutes.