The results presented in the paper by Iwe et al. “Technical note: New approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer on voluntary observing ships” can be reproduced using this data.

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Performance GAM 2000_Table 1.xlsx

The data can be used to reproduce the results presented in Table 1. 

column A: time in seconds
column B-BI: mole fraction in % (60 measurements in total)

worksheets are named as follows: gas analyzed_detector used

The mass spectrometer was calibrated with standard gas of the following composition: x(N2) = 78.1 %, x(O2) = 20.9 %, x(Ar) = 1.0 %

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Accuracy and Precision_Figure2_Table2.xlsx

The data can be used to reproduce the results presented in Figure 2 and Table 2.

column A-F: date and time specifications
column G: time of the specific measurement in seconds
column H: time of the specific measurement in minutes
column I: salinity of the water in PSU
column J: temperature of the temperature controlled water bath in °C
column K: temperature of the water in front of the membrane equilibrator in °C
column L: total pressure on the gas side of the membrane equilibrator in mbar
column M-O: partial mole fraction of the respective gases in %
column P: temperature of the water in front of the membrane equilibrator in K
column Q: partial pressure of the water in atm (calculated using Ambrose and Lawrenson (1972), using temperature of the water in front of the membrane equilibrator)
column R: partial pressure of the water in mbar
column S: total pressure on the gas side of the membrane equilibrator in mbar, substracted by partial pressure of the water
column T-V: partial pressure of the respective gases in mbar
column W-Y: bunsen coefficients for the respective gases in (mol/L)/atm (N2 and Ar calculated using Hamme and Emerson (2004) and O2 calculated using Weiss (1970))
column Z-AB: concentration of the respective gases in µmol/L
column AC: (insitu) partial pressure of the water in mbar (calculated using Ambrose and Lawrenson (1972), using temperature of the controlled water bath, for calculation of O2 saturation concentration)
column AD: (insitu) partial pressure of the water in atm
column AE: (insitu) bunsen coefficient of O2 in (mol/L)/atm (calculated using Weiss (1970), using temperature of the controlled water bath)
column AF-AH: saturation concentrations for the respective gases in µmol/L 
column AI-AK: concentration difference between the measured concentration and the expected saturation concentration for the respective gases in µmol/L
column AL-AQ: determination of the water density using the temperature of the controlled water bath ( Mostafa H. Sharqawy, John H. Lienhard V & Syed M. Zubair (2010): Thermophysical properties of
seawater: a review of existing correlations and data, Desalination and Water Treatment, 16:1-3, 354-380)
column AR-AS: saturation concentrations for the respective gases in µmol/kg (calculated using Hamme and Emerson (2004))
column AW-BF: determination of the water density and saturation concentration for N2 and Ar using the temperature in front of the membrane equilibrator to calculate the bunsen coefficient (column W and Y)

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Measurement of tau_Figure4.xlsx

The data can be used to reproduce the results presented in Figure 4 and to calculate the equilibration times presented in section 3.2.2

column A: time in minutes
column B: mole fraction in %
column C: total pressure on the gas side of the membrane equilibrator in mbar
column D: temperature of the water in front of the membrane equilibrator in K
column E: partial pressure of the water in mbar (calculated using Ambrose and Lawrenson (1972), using temperature of the water in front of the membrane equilibrator)
column F: partial pressure of CO2 in mbar (assuming 400 ppm)
column G: total pressure on the gas side of the membrane equilibrator in mbar, substracted by partial pressure of water and CO2
column H: partial pressure in mbar
column I: ln [p (t) - p (eq)]
column K: equilibrium partial pressure (given by the plateaud partial pressure after equilibration, always the last measured partial pressure)

worksheets are named as follows: τ (gas)_measurement number (The addition "Figure4" means that this data was used to create Figure 4)

Data of τ (N2)_1-3 was collected on one day
Data of τ (O2)_1 and τ (Ar)_1 was collected on one day (same equilibration process)
Data of τ (O2)_2 and τ (Ar)_2 was collected on one day (same equilibration process)
Data of τ (O2)_3 and τ (Ar)_3 was collected on one day (same equilibration process)






