Hamme et al. (2019) Global noble gas and N2/Ar database, version 1.0 Data Originators: Roberta Hamme, William Jenkins, Steven Emerson, David Nicholson, Rachel Stanley Date: 7 August 2018 This database contains the data on dissolved gas measurements published in Roberta C. Hamme, David P. Nicholson, William J. Jenkins, and Steven R. Emerson (2019) Using noble gases to assess the ocean's carbon pumps, Annual Review of Marine Science, 11, p. 75-103, doi:10.1146/annurev-marine-121916-063604 This data is provided free for educational and non-profit research purposes. We ask that you appropriately cite this publication in any work that uses this database. Please also send an e-mail to rhamme@uvic.ca, letting me know that you have downloaded the data, so that I can keep you apprised of any further corrections or changes. If you discover what you believe to be an error in the database, it is your responsibility to send an e-mail to me at rhamme@uvic.ca before using the data in a publication. Both MatLab .mat databases and comma-delimited .csv text files are provided. These two formats contain identical information. Different cruises can be identified by the sequence number, cruisename, or date. Secondary data - On some cruises, Ar concentration and N2/Ar ratio measurements were performed at two different labs on separate samples, for inter-calibration purposes. In these cases, data from both labs is given separately with data from the second lab labeled "secondary". Methods University of Victoria - Water samples were collected through CO2-flushed tubing into evacuated flasks until half-full. The water was equilibrated with the headspace and then removed. Noble gas samples were determined following a method similar to that described in Hamme, R.C., and J.P. Severinghaus (2007) "Trace gas disequilibria during deep-water formation", Deep Sea Research I, 54(6), p. 939-950 but with a helium rather than nitrogen balance gas. Gas samples were purified through a -90oC trap to remove water vapor and exposed to a hot getter to remove all but the noble gases. A calibrated aliquot of 38Ar was added along with compressed helium to bring the pressure back up. Samples were then measured for Ar isotopes and Ne/Ar and Kr/Ar ratios on a MAT 253 isotope ratio mass spectrometer. Absolute Ar concentrations were determined by Ar isotope dilution with the added 38Ar, while the ratio measurements were combined with the absolute Ar concentrations to yield Ne and Kr concentrations. Noble gas standards were calibrated relative to air with assumed dry mole fractions of 1.818e-5 for Ne, 9.34e-3 for Ar, and 1.141e-6 for Kr. N2/Ar measurements were determined following the method described in Emerson et al. (1999) "Accurate measurement of O2, N2, and Ar gases in water and the solubility of N2", Marine Chemistry, volume 64, p. 337-347. Gas samples were purified though a trap in liquid nitrogen to remove water vapor and carbon dioxide. Samples were then measured for N2/Ar ratios on a MAT 253 mass spectrometer. N2/Ar standard gases were calibrated relative to air with assumed dry mole fractions of 9.34e-3 for Ar and 0.78084 for N2. Woods Hole Oceanographic Institution - Noble gas samples analyzed at Woods Hole Oceanographic Institution were determined following variants of the method described in Stanley R.H.R., B. Baschek, D.E. Lott, and W.J. Jenkins (2009) "A new automated method for measuring noble gases and their isotopic ratios in water samples", Geochemistry, Geophysics, Geosystems, volume 10, Q05008, doi:10.1029/2009GC002429. Water samples were collected into stainless steel containers for cruises in 2008 and prior (Bermuda Atlantic Time-series Study cruises and CLIVAR I6S) or into crimped copper tubes for cruises occurring in 2009 and later. All the dissolved gas was extracted from the water and then purified through a cryotrap to remove water vapor and exposed to a hot getter to remove all the the noble gases. The noble gases were then frozen into two cryotraps, allowing each noble gas to be sequentially released for analysis in a quadrupole mass spectrometer. Noble gas concentrations were determined by peak height manometry for all gases and samples, except the most recent Kr and Xe data measured from the eastern tropical Pacific, which use a new isotope dilution method . Noble gas standards were calibrated relative to air with assumed dry mole fractions of 5.24e-6 for He, 1.818e-5 for Ne, 9.34e-3 for Ar, 1.141e-6 for Kr, and 8.7e-8 for Xe. Scripps Institution of Oceanography - Water samples were collected through CO2-flushed tubing into evacuated flasks until half-full. The water was equilibrated with the headspace and then removed. Noble gas samples were determined following the method described in Hamme, R.C., and J.P. Severinghaus (2007) "Trace gas disequilibria during deep-water formation", Deep Sea Research I, 54(6), p. 939-950. Gas samples were purified through a -90oC trap to remove water vapor and exposed to a hot getter to remove all but the noble gases. A calibrated aliquot of 38Ar was added along with compressed nitrogen to bring the pressure back up. Samples were then measured for Ar isotopes and Kr/Ar ratios on a MAT 252 isotope ratio mass spectrometer. Absolute Ar concentrations were determined by Ar isotope dilution with the added 38Ar, while the ratio measurements were combined with the absolute Ar concentrations to yield Kr concentrations. Noble gas standards were calibrated relative to air with assumed dry mole fractions of 9.34e-3 for Ar, and 1.141e-6 for Kr. N2/Ar measurements were determined following the method described in Kobashi, T., J.P. Severinghaus, and K. Kawamura (2008) "Argon and nitrogen isotopes of trapped air in the GISP2 ice core during the Holocene epoch (0-11,500 B.P.): Methodology and implications for gas loss processes", Geochimica et Cosmochimica Acta, 72 (19), 4675-4686, doi:10.1016/j.gca.2008.07.006. Gas samples were purified though a trap in liquid nitrogen to remove water vapor and carbon dioxide and then through heated copper to remove oxygen. Samples were then measured for N2/Ar ratios on a MAT 252 mass spectrometer. N2/Ar standard gases were calibrated relative to air with assumed dry mole fractions of 9.34e-3 for Ar and 0.78084 for N2. University of Washington - Water samples were collected through CO2-flushed tubing into evacuated flasks until half-full. The water was equilibrated with the headspace and then removed. Neon samples were determined following the method described in Hamme, R.C., and S.R. Emerson (2004) "Measurement of dissolved neon by isotope dilution using a quadrupole mass spectrometer", Marine Chemistry, 91(1-4), p. 53-64, doi:10.1016/j.marchem.2004.05.001. A calibrated aliquot of 22Ne was added to the sample flasks before sampling. Gas samples were purified though a trap in liquid nitrogen to remove water vapor and carbon dioxide and then through an activated charcoal trap in liquid nitrogen to remove argon and heavier gases. Samples were then measured for Ne isotopes on a quadrupole mass spectrometer. Absolute Ne concentrations were determined by Ne isotope dilution with the added 22Ne. The spike aliquot was calibrated relative to air with assumed dry mole fractions of 1.818e-5 for Ne. Ar concentration and N2/Ar ratios were determined by two different methods. Samples collected in 2001 and earlier were determined following the method described in Emerson et al. (1999) "Accurate measurement of O2, N2, and Ar gases in water and the solubility of N2", Marine Chemistry, volume 64, p. 337-347. Gas samples were purified though a trap in liquid nitrogen to remove water vapor and carbon dioxide. Samples were then measured for N2/Ar and O2/Ar ratios on a MAT 251 mass spectrometer. For the samples collected near Bermuda in 2001, the O2/Ar ratio measurements were combined with absolute O2 concentrations determined by Winkler titration to yield Ar concentrations. More recent Ar concentration and N2/Ar ratio measurements were determined following the method described in Emerson, S., T. Ito, and R.C. Hamme (2012) "Argon supersaturation indicates low decadal-scale vertical mixing in the ocean thermocline", Geophysical Research Letters, 39, L18610, doi:10.1029/2012GL053054. Gas samples were purified though a trap in liquid nitrogen to remove water vapor and carbon dioxide and then a calibrated aliquot of 36Ar was added. Samples were then measured for Ar isotopes and N2/Ar ratios on a Delta X/L isotope ratio mass spectrometer. Absolute Ar concentrations were determined by Ar isotope dilution with the added 36Ar. Ar and N2/Ar gas standards were calibrated relative to air with assumed dry mole fractions of 9.34e-3 for Ar and 0.78084 for N2. Through rigorous method inter-comparison and repeated laboratory comparison of oxygen concentration determined by isotope dilution and Winkler titration, Ar concentration samples analyzed by this 36Ar isotope dilution method have been found to be 0.7% too low. Accordingly, the Ar concentration and Ar saturation anomaly data from this method have all be increased by 0.7% in this database. Kr/Ar samples were determined following a method similar to that described in Hamme, R.C., and J.P. Severinghaus (2007) "Trace gas disequilibria during deep-water formation", Deep Sea Research I, 54(6), p. 939-950. Gas samples were purified through a -90oC trap to remove water vapor and exposed to a hot getter to remove all but the noble gases. Compressed nitrogen was added to bring the pressure back up. Samples were then measured for Kr/Ar ratios on a MAT 253 isotope ratio mass spectrometer. Noble gas standards were calibrated relative to air with assumed dry mole fractions of 9.34e-3 for Ar, and 1.141e-6 for Kr. Quality control - Samples measured at University of Victoria, Scripps Institution of Oceanography, and University of Washington were nearly all collected in duplicate. For these samples in this database, only data where both duplicates were analyzed successfully and where their standard deviation was less than three times the pooled standard deviation are included. Noble gas duplicates were required to be within 0.93% of each other for Ne, within 0.28% for Ar, and within 0.35% for Kr. Similarly N2/Ar duplicates were required to be within 0.17% of each other. Both duplicates are present in the database. The exception to this is the N2/Ar data collected in 2007 in the Labrador Sea and analyzed at Scripps Institution of Oceanography. These samples were not collected in duplicate but are present in the database. For samples collected at the Bermuda Atlantic Time-series Study and in the Southern Ocean that were analyzed at Woods Hole Oceanographic Institution, we binned the data by depth for each cruise and removed samples that were outside three times the standard deviation of samples within each depth bin. For the 2010-2011 Atlantic GEOTRACES transect samples that were analyzed at Woods Hole Oceanographic Institution, we simply removed data where the Ne saturation anomaly was less than -10% or larger than 5%. For the 2013 Pacific GEOTRACES transect samples that were analyzed at Woods Hole Oceanographic Institution, we removed Xe measurements analyzed by peak height manometry, retaining only those analyzed by isotope dilution. NaN = missing data. Variable naming convention: sequence - An sequential numerical identifier for each cruise, unique to this database. cruisename - cell array of strings in MatLab, a string in the csv file. The EXPO number is listed first, followed by a colon, followed by colloquial cruise names, followed by a colon, followed by the ship name. lat or latitude - The latitude of the station in oN. lon or longitude - The longitude of the station in oE. Negative numbers indicate oW. event - number of the event that the water samples were drawn from. Event is used when each cast in a cruise has its own unique number. station - number of the station that the water samples were drawn from. Station is used when each station (location) in a cruise has its own unique number but multiple casts occurred at a given station number. cast - - number of the cast at an individual station that the water samples were drawn from. Cast is used when multiple casts occurred at a given station number. niskin - number of the niskin bottle or rosette position that the water samples were drawn from. date - This is the date that samples were collected. In the MatLab database, this is in the MatLab datenum format. In the csv files it is listed as separate year, month, and date. press - Pressure in dbar. CTDtemp - in situ temperature measured by the CTD in oC on the ITS-90 Temperature Scale. CTDsal - salinity measured by the CTD, expressed on the PSS-78 scale. analysis lab - a number indicating which lab the analyses were performed in. 1 = University of Victoria, 2 = Woods Hole Oceanographic Institution, 3 = Scripps Institution of Oceanography, 4 = University of Washington. analysis lab secondary - for cruises where Ar concentration or N2/Ar ratio were measured in more than one lab, this number indicates which lab the analyses listed in the "secondary" columns were performed in. 1 = University of Victoria, 2 = Woods Hole Oceanographic Institution, 3 = Scripps Institution of Oceanography, 4 = University of Washington. He conc - dissolved He concentration in umol/kg. These concentration values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Ne conc - dissolved Ne concentration in umol/kg. These concentration values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Ar conc - dissolved Ar concentration in umol/kg. These concentration values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Ar conc secondary - same as for Ar conc but data is from independent samples collected from the same cruise and analyzed in a second laboratory. Kr conc - dissolved Kr concentration in umol/kg. These concentration values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Xe conc - dissolved Xe concentration in umol/kg. These concentration values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Ne/Ar - dissolved Ne/Ar ratio with no units. These ratio values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Kr/Ar - dissolved Kr/Ar ratio with no units. These ratio values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. N2/Ar - dissolved N2/Ar ratio with no units. These ratio values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. N2/Ar secondary - same as for N2/Ar but data is from independent samples collected from the same cruise and analyzed in a second laboratory. depth - Depth in meters. ptmp - Potential temperature in oC and referenced to the surface. sigma-theta - Potential density of the seawater expressed in sigma units and referenced to the surface. Hesat - Saturation anomaly of He in percent. 0% indicates that the He concentration is equal to that expected at equilibrium for the potential temperature and salinity of the water. ie. Hesat = (He/Heeq - 1) *100 The He saturation anomaly is calculated relative to the solubility curve of Weiss, R.F. (1971) "Solubility of Helium and Neon in Water and Seawater", Journal of Chemical and Engineering Data, 16(2), 235-241. These saturation anomaly values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Nesat - Saturation anomaly of Ne in percent. 0% indicates that the Ne concentration is equal to that expected at equilibrium for the potential temperature and salinity of the water. ie. Nesat = (Ne/Neeq - 1) *100 The Ne saturation anomaly is calculated relative to the solubility curve of Hamme, R.C., S.R. Emerson (2004) "The solubility of neon, nitrogen and argon in distilled water and seawater", Deep-Sea Research I, 51(11), p. 1517-1528. These saturation anomaly values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Arsat - Saturation anomaly of Ar in percent. 0% indicates that the Ar concentration is equal to that expected at equilibrium for the potential temperature and salinity of the water. ie. Arsat = (Ar/Areq - 1) *100 The Ar saturation anomaly is calculated relative to the solubility curve of Hamme, R.C., S.R. Emerson (2004) "The solubility of neon, nitrogen and argon in distilled water and seawater", Deep-Sea Research I, 51(11), p. 1517-1528. These saturation anomaly values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Arsat secondary - same as for Arsat but data is from independent samples collected from the same cruise and analyzed in a second laboratory. Krsat - Saturation anomaly of Kr in percent. 0% indicates that the Kr concentration is equal to that expected at equilibrium for the potential temperature and salinity of the water. ie. Krsat = (Kr/Kreq - 1) *100 Kr saturation anomaly is calculated relative to the solubility curve of Weiss, R.F., and T.K. Kyser (1978) "Solubility of Krypton in Water and Seawater", Journal of Chemical Thermodynamics, 23(1), 69-72. These saturation anomaly values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Xesat - Saturation anomaly of Xe in percent. 0% indicates that the He concentration is equal to that expected at equilibrium for the potential temperature and salinity of the water. ie. Xesat = (Xe/Xeeq - 1) *100 The Xe saturation anomaly is calculated relative to the solubility curve of D. Wood and R. Caputi (1966) "Solubilities of Kr and Xe in fresh and sea water", U.S. Naval Radiological Defense Laboratory, Technical Report USNRDL-TR-988, San Francisco, CA, pp. 14. These saturation anomaly values are from individual samples. Where a duplicate from the same Niskin was collected and analyzed, the duplicate's value is listed in the second column with the same label. Ne/Arsat - Saturation anomaly of Ne/Ar ratio in percent. 0% indicates that the Ne/Ar ratio is equal to that expected at equilibrium for the potential temperature and salinity of the water, ie. Ne/Arsat = ((Ne/Ar) / (Neeq/Areq) - 1) * 100. Ne/Ar saturation anomaly is calculated relative to the solubility curves of Hamme, R.C., S.R. Emerson (2004) "The solubility of neon, nitrogen and argon in distilled water and seawater", Deep-Sea Research I, 51(11), p. 1517-1528. Kr/Arsat - Saturation anomaly of Kr/Ar ratio in percent. 0% indicates that the Kr/Ar ratio is equal to that expected at equilibrium for the potential temperature and salinity of the water, ie. Kr/Arsat = ((Kr/Ar) / (Kreq/Areq) - 1) * 100. Kr/Ar saturation anomaly is calculated relative to the Ne solubility curve of Hamme, R.C., S.R. Emerson (2004) "The solubility of neon, nitrogen and argon in distilled water and seawater", Deep-Sea Research I, 51(11), p. 1517-1528 and the Kr solubility curve of Weiss, R.F., and T.K. Kyser (1978) "Solubility of Krypton in Water and Seawater", Journal of Chemical Thermodynamics, 23(1), 69-72. N2/Arsat - Saturation anomaly of N2/Ar ratio in percent. 0% indicates that the N2/Ar ratio is equal to that expected at equilibrium for the potential temperature and salinity of the water, ie. N2Arsat = ((N2/Ar) / (N2eq/Areq) - 1) * 100. N2/Ar saturation anomaly is calculated relative to the solubility curves of Hamme, R.C., S.R. Emerson (2004) "The solubility of neon, nitrogen and argon in distilled water and seawater", Deep-Sea Research I, 51(11), p. 1517-1528. N2/Arsat secondary - same as for N2/Arsat but data is from independent samples collected from the same cruise and analyzed in a second laboratory.