Water column dissolved radium-226 from 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 (NCEI Accession 0291448)

This dataset contains chemical data collected on R/V Roger Revelle during cruise RR1814 from 2018-09-24 to 2018-10-21. These data include depth and radium-226. The instruments used to collect these data include Niskin bottle and Radium Delayed Coincidence Counter. These data were collected by Willard S. Moore of University of South Carolina and Matthew A. Charette of Woods Hole Oceanographic Institution as part of the "Collaborative Research: US GEOTRACES PMT: Sources and Rates of Trace Element and Isotope Cycling Derived from the Radium Quartet (PMT Radium Isotopes)" and "US GEOTRACES Pacific Meridional Transect (U.S. GEOTRACES PMT)" projects and "U.S. GEOTRACES (U.S. GEOTRACES)" program. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2021-01-14.

The following is the text of the dataset description provided by BCO-DMO:

Water column dissolved radium-226 from Leg 1 of PMT cruise

Dataset Description:
Acquisition Description:
At sea, ²²⁶Ra samples were collected following the GEOTRACES cookbook. Samples were collected from a 30L Niskin mounted directly above McLane large volume in situ pump WTS-LV (>1000 m) or on a CTD Rosette (<1000 m). These samples (10-25 L) were gravity filtered through 15 g of manganese oxide impregnated acrylic fiber at approximately 0.5L/min. The filtrate was collected inside of a graduated rigid sided container and the volume was recorded. A mass was also obtained by using a hand-held digital balance.

The Mn fiber from the Niskin bottles were rinsed with deionized water back at WHOI, partially dried, and sealed within a fiber holder after being flushed with helium equivalent to 30 column volumes. Samples were stored for a minimum of 12 days and analyzed for ²²⁶Ra via ²²²Rn ingrowth using alpha scintillation counting (Key et al., 1979). Samples were counted for 1-20 hours depending on the activity on the fiber, which resulted in counting uncertainties of ~2% dependent upon ²²⁶Ra content on the fiber and sample volume.