Activity of actinium-227 from water samples collected on Leg 2 (Hilo, HI to Papeete, French Polynesia) of the US GEOTRACES Pacific Meridional Transect (PMT) cruise (GP15, RR1815) on R/V Roger Revelle from Oct-Nov 2018

Actinium-227 (227Ac) was captured on commercial water filters impregnated with manganese dioxide (MnO2) and placed downstream of the filters in submersible pumps deployed on GEOTRACES expedition GP15, aboard R/V Roger Revelle, in collaboration with groups from Woods Hole Oceanographic Institution (WHOI) and University of South Carolina who measured radium isotopes on the same cartridges. The activity of 227Ac was measured using RaDeCC (Radium Delayed Coincidence Counter) and used to calculate the concentration of dissolved 227Ac along the transect by PI Douglas Hammond and graduate student Nathan Kemnitz. Data have been summarized and will be submitted in a publication to be submitted to JGR Oceans, along with a companion data set for 227Ac, 228Ra, and 210Pb in sediments. This dataset has been used to evaluate deep ocean solute transport. This dataset includes data from Leg 2 of the cruise (RR1815). Leg 1 data (RR1814) are available in a separate BCO-DMO dataset.