Dataset: Depth profiles of seawater particulate 232Th, 230Th, and 231Pa from R/V Sonne cruise SO245 (UltraPac, GPpr09) during Dec 2015 to Jan 2016

This dataset contains depth profiles of seawater particulate 232Th, 230Th, and 231Pa from R/V Sonne cruise SO245 (UltraPac, GPpr09).

Dataset Notes:
Radionuclide concentrations are given as micro-Becquerel (10-6 Bq, µBq or micro-Bq) per kg seawater for 230Th and 231Pa, and pmol (10-12 mol) per kg seawater for 232Th. A Becquerel is the SI unit for radioactivity and is defined as 1 disintegration per second. These units are recommended by the GEOTRACES community.

The "total particulate" (TP) data refers to the particle size class >0.8µm. The particulate samples were collected by in-situ pumping over paired 0.8m Pall Supor800 polyethersulfone filters (See Lam et al. 2015 for particulate sampling methodology, noting that our deployments did not include a >51 µm prefilter). Analysis of the paired Supor filters represents a particle size class approximating >0.45 µm (Bishop et al. 2012), while the top filter alone represents >0.8 µm and it is this size class referred to here as the total particulate fraction. On previous sampling campaigns, we measured a select number of top and bottom filters separately for radionuclides and found that the bottom filters had radionuclide levels that were indistinguishable from clean filter process blanks. Therefore whether or not samples were analyzed as top and bottom paired, or the top filter alone, we infer the total particulate data to represent >0.8 µm particles.

Parameter names are adopted based on a recommendation from the GEOTRACES community (http://www.egeotraces.org/Parameter_Naming_Conventions.html)