Publicly Available Data

W. J. Jenkins
November, 2018

A Global Oceanic Tritium-Helium Dataset

About this data

This data set contains a compilation of oceanic tritium and helium isotope measurements along with relevant metadata obtained from a range of data repositories, publications, and contributions from our collaborators. These measurements have been made by a large number of individuals from a wide range of institutions throughout the world. We provide this data in the hopes of it being useful to all.

If you have issues, corrections, or questions about specific data records, we ask you to email wjenkins@whoi.edu with the data set version number (currently 2018.09, but please check with the file) and one of the following:

If a specific (or a few) data point(s), provide us with the unique record_id number(s) and your question/correction/concerns.
If one or a few stations, provide us with the expocode, section_id, and station number(s).
If an entire section, cruise, or larger data set, provide us with the expocode plus any defining information to help us identify the samples.

The data set consists of three tables: the main data table, a table of references, and an email list. You can obtain all of these in a single database file, or download the compressed ("zip") files in either spreadsheet or text format. Given spreadsheet size limitations, the main data table is split into two parts, so you will need to have all four files in either XLSX or CSV format.

The MATLAB zip file contains the main table only in native binary format, so we have included the references and email list in CSV format. The data consists of 39 column vectors with names the field names in the database (see the README.TXT file). Numeric fields are double precision vectors, and text fields are cell vectors.

The PSQL is a zipped plain-text file that acts as a backup for a PostgreSQL database. You can execute this file as a series of SQL commands to build the database in PostgreSQL. A public domain version of the PostgreSQL server is available for download at https://www.postgresql.org/download/

More formats will be added as time goes by.

Noble Gas Solubility Measurements

We have determined the concentrations of atmospheric helium, neon, argon, krypton, and xenon in fresh water and seawater equilibrated with moist marine air at one atmosphere over a temperature range from near freezing point to approximately 35°C and a salinity range of zero to roughly 39.5 PSU. In all, we made 74 He-Xe measurements at 34 distinct temperature and salinity combinations. The experiments included 35 replicate pairs of samples drawn from 35 separate equilibrations, which in turn had two repeat equilibrations run at close to identical temperatures. We fit the results to a seven-parameter function commonly used to compute solubility equilibrium concentrations of these gases for environmental waters. Based on an estimate of analytical accuracy, reproducibility of the comparison with secondary atmospheric standards, and replicate sample reproducibility, we estimate this function to predict equilibrium concentrations to overall precisions 0.10% or better. This includes the regression statistics associated with interpolation/extrapolation errors fitting the 7-parameter smoothing function. There is an overall systematic uncertainty of 0.15% for all gases, based on our confidence in and experience with the integrity and cross-calibration of our air standards over recent years. Because our methods are calibrated using assumed and explicit atmospheric abundances of these noble gases, any subsequent uncertainties in atmospheric abundances cancel out in the determination. Moreover, measurement at ambient atmospheric abundances avoids any potential co-solvency induced biases introduced by using ~1 atmosphere pure noble gases, as has been done in most previous studies. We compare these determinations to those made by others in the past and find modest but significant systematic differences with those results.

The results of our measurements (raw data) are available in an EXCEL spreadsheet (check the right hand side of this web page), and the coefficients of the seven parameter solubility function as well. We also supply two MATLAB files (a script m-file plus a necessary data mat-file).

If you use these solubility functions, please cite the following reference:

Jenkins, W.J., Lott, D.E., III and Cahill, K.L. (2019) A Determination of Atmospheric Helium, Neon, Argon, Krypton, and Xenon Solubility Concentrations in Water and Seawater. Marine Chemistry 211, 94-107.