N. J. Jenkins et al.: A comprehensive global oceanic dataset of helium isotope and tritium measurements 
444 
Table 3. Contributing analysts that are not authors on this paper. 
+ 
» 10 16 20 zo 30 35 
S°He (%) on 2500 m 
40 
Figure 8. A map of 5°He values at approximately 2500 m depth. 
The values plotted are simply an average of all measurements within 
a 1° square between 2250 and 2750 dbar. Depths shallower than 
2500 m are masked in gray, and sampling locations are indicated by 
jight gray dots. 
5 10 15 20 za 30 35 
S°He (%) on 4000 m 
40 
Figure 9. A map of $°He values at approximately 4000 m depth. 
The values plotted are simply an average of all measurements within 
a 1° square between 3750 and 4250 dbar. Depths shallower than 
4000 m are masked in gray, and sampling locations are indicated by 
light gray dots. 
5 Contributors and pioneers 
This dataset represents the hard work over many decades of 
numerous individuals that are not included in the authorship 
list of this paper. We list their names and affiliations at the 
time of their contributions in Table 3. The list focuses on 
those who made the measurements rather than those who 
may have used the data. We apologize if there are others that 
we may have missed in this list. 
We also would like to recognize that the ability to make the 
measurements presented in this dataset was a consequence 
of the pioneering work of more than a few inventive and tal- 
ented individuals. While space does not permit mentioning 
chem all here, we felt it appropriate to highlight a pair of pio- 
neering scientists who conducted landmark studies on ocean 
tritium and ?He measurements. 
www.earth-syst-sci-data.net/11/441/20 19 
Arnold E. Bainbridge 
Reinhold Bayer 
Friedrich Begemann 
Ulrich Beyerle 
Wallace S. Broecker 
Martin Butzin 
William Brian Clarke 
K. O. Dockins 
H. Gorman Dorsey 
Eric Eriksson 
Elise Fourre 
Bruno J. Giletti 
Aristid von Grosse 
". R. Harries 
TI. Kaji 
Sheldon Kaufman 
J. Laurence Kulp 
Willard F. Libby 
Dempsey E. Lott III 
Andrea Ludin 
Liliane Merlivat 
Robert Michel 
Yasuo Miyake 
Karl-Otto Munnich 
Alfred O. Nier 
Masami Nonaka 
Hans Göte Östlund 
Clare F. Postlethwaite 
Paul D. Quay 
Rachel S. H. R. Stanley 
Sheila Stark 
Reiner Steinfeldt 
Hans E. Suess 
Turgen Sültenfuss 
Naoto Takahata 
A. Tamuly 
C. B. Taylor 
Zafer Top 
Tom Torgersen 
Kim A. Van Scoy 
Carolyn Walker 
Wolfgang Weiss 
Peter M Williams 
UCSD, La Jolla, CA, USA 
U. Heidelberg, Heidelberg, Germany 
U. Chicago, Chicago, IL, USA 
ETH, Zurich, Switzerland 
LDEO, Pallisades, NY, USA 
University of Bremen, Bremen, Germany 
McMaster University, Hamilton, ON, Canada 
UCSD, La Jolla, CA, USA 
RSMAS, Miami, FL, USA 
IMS, Stockholm, Sweden 
CEA-Saclay, France 
LDEO, Pallisades, NY, USA 
RITU, Philadelphia, PA, USA 
Australian AEC, Sutherland, NSW, Australia 
Kyushu University, Fukuoka, Japan 
U. Chicago, Chicago, IL, USA 
LDEO, Pallisades, NY, USA 
U. Chicago, Chicago, IL, USA 
WHOI, Woods Hole, MA, USA 
LDEO, Pallisades, NY, USA 
Sorbonne University, Paris, France 
UCSD, La Jolla, CA, USA 
GRA, Tokyo, Japan 
U. Heidelberg, Heidelberg, Germany 
U. Minnesota, Minneapolis, MN, USA 
IPRC & SOES, Tokyo, Japan 
RSMAS, Miami, FL, USA 
NOC-SOES, Southampton, UK 
University of Washington, Seattle, WA, USA 
WHOI, Woods Hole, MA, USA 
NOC-SOES, Southampton, UK 
IUP, University of Bremen, Germany 
UCSD, La Jolla, CA, USA 
{UP, University of Bremen, Germany 
ORI, University of Tokyo, Tokyo, Japan 
University of Quebec, Rimouski, PQ, Canada 
INS, Lower Hutt, New Zealand 
RSMAS, Miami, FL, USA 
WHOI, Woods Hole, MA, USA 
RSMAS, Miami, FL, USA 
WHOI, Woods Hole, MA, USA 
UV. Heidelberg, Heidelberg, Germany 
TICSD. La Talla. CA. USA 
5.1 W. Brian Clarke (1937-2002) 
Although not the first to measure °He/*He in the environ- 
ment (that was done by Aldrich and Nier, 1948), Clarke made 
the first reported helium isotope measurements in seawater 
(Clarke et al., 1969). He made his first measurements us- 
ing a modified single stage magnetic sector, single collector 
mass spectrometer to a precision of about 2 %. Clarke de- 
veloped the first compact all-metal branch tube mass spec- 
trometer specifically designed to make °He/*He measure- 
ments ultimately to a precision of 0.1 % to 0.2 %. At the 
time, conventional wisdom dictated that such measurements 
(let alone precision measurements) were not possible with a 
single stage magnetic sector instrument for such high (10°) 
abundance ratios, but Clarke forged ahead anyway. He ini- 
tially constructed two instruments in the early 1970s, using 
Earth Syst. Sci. Data, 11, 441-454, 2019