Publication Date:
2024-05-19
Description:
The ²³⁴Th-²³⁸U radioactive pair has been extensively used to evaluate the efficiency with which photosyntetically fixed carbon is exported from the surface ocean by means of the biological pump since the 90's. The seminal work of Buesseler et al. (1992) proposed that particulate organic carbon (POC) flux can be indirectly calculated from ²³⁴Th distributions if the ratio of POC to ²³⁴Th measured on sinking particles (POC:²³⁴Th) at the desired export depth is known. Since then, a huge amount of ²³⁴Th depth profiles have been collected using a variety of sampling instruments and strategies that have changed along years.
This is a global oceanic compilation of ²³⁴Th measurements, that collects results from innumerable researchers and laboratories over a period exceeding 50 years. The present compilation is made of a total 223 datasets: 214 from studies published either in articles in referred journals, PhD thesis or repositories, and 9 unpublished datasets. Including measurements from JGOFS, VERTIGO and GEOTRACES programs, with sampling from approximately 5000 locations spanning all the oceans.
The compilation includes total ²³⁴Th profiles, dissolved and particulate ²³⁴Th concentrations, and POC:²³⁴Th ratios (both from pumps and sediment traps) for two sizes classes (1-53 μm and 〈 53 μm) when available.
Appropriate metadata have been included, including geographic location, date, and sample depth, among others. When available, we also include water temperature, salinity, ²³⁸U data and particulate organic nitrogen data. Data sources and methods information (including ²³⁸U and ²³⁴Th) are also detailed along with valuable information for future data analysis such as bloom stage and steady/non-steady state conditions at the sampling moment. This undertaking is a treasure of data to understand and quantify how oceanic carbon cycle functions and how it will change in future.
The compilation can be downloaded in three different ways:
1) A single merged file including all the individual excel files. This option can be accessed under "Other version: More than 50 years of Th-234 data: a comprehensive global oceanic compilation (single xlsx file)".
2) A summary table that includes details from cruise, sampling dates, techniques applied, authors and DOI of the compiled ²³⁴Th data, among others, each line corresponds to a specific dataset. The table can be accessed by clicking ""View dataset as HTML" and downloaded in "Download dataset as tab-delimited text".
3) Individual Excel files for each dataset can be manually chosen from the summary table, corresponding to the complete ²³⁴Th dataset and metadata from a specific publication or program. This option is available by clicking "View dataset as HTML". Furthermore, all files referred to can be downloaded in one go as ZIP or TAR.
Keywords:
234Th; Author(s); Binary Object; biological carbon pump; Carbon, organic, particulate/Thorium-234 ratio; carbon export; Chief scientist(s); Cruise/expedition; DATE/TIME; ELEVATION; Gear; GEOTRACES; Global marine biogeochemical cycles of trace elements and their isotopes; JGOFS; Joint Global Ocean Flux Study; Journal/report title; LATITUDE; LONGITUDE; Multiple cruises/expeditions; Ocean; Ocean and sea region; Period; POC flux; Project; Reference of data; Thorium-234, dissolved; Thorium-234, particulate; Thorium-234, total; Uniform resource locator/link to reference; Uranium-238; Vessel; Year of publication
Type:
Dataset
Format:
text/tab-separated-values, 4056 data points
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