Science Data Processing Notes:

CLE-AdCSV data was interpreted using a freely available interpretation program, ProMCC (Omanovic et al. 2015; https://sites.google.com/site/daromasoft/home/promcc), which employs matrix based optimization of titration data fitting to obtain ligand concentrations and conditional stability constants for each sample. Uncertainties in the fitted parameter are presented as the 95% confidence interval provided by the interpretation program. When replicate titrations were conducted, results are presented as averages of the replicates.

Dissolved iron (DFe) concentrations determined by inductively coupled plasma-mass spectrometry (ICP-MS) by Bettina Sohst in project PI Peter Sedwick’s lab at Old Dominion University were used in the ProMCC interpretation program to calculate ligand concentrations and conditional stability constants from the sample titrations. The DFe values used for this dataset are provided in the speciation submission for reference, please see Sedwick’s dataset for the complete dissolved iron data and metadata.

The detection limit for the electroactive Fe-SA complex has been found to be 0.01 nM (Buck et al. 2007), calculated as three times the standard deviation of measured peak height from a 0.05 nM Fe addition to UV-oxidized and chelexed seawater with a 900 s deposition time. For a 90 s deposition time, the detection limit for Fe-SA is ~0.1 nM (Buck et al. 2018).

Data flag notes:

The standard Ocean Data View qualifying flags were used within the flag columns of the dataset (reference all flags at https://www.bodc.ac.uk/resources/delivery_formats/odv_format/):

1: Good Value: Good quality data value that is not part of any identified malfunction and has been verified as consistent with real phenomena during the quality control process. [Used when data were shown to be reproducible]

2: Probably Good Value: Data value that is probably consistent with real phenomena but this is unconfirmed or data value forming part of a malfunction that is considered too small to affect the overall quality of the data object of which it is a part. [Used when the reported value reflects analysis of a single or unverified replicate]

3: Probably Bad Value: Data value recognized as unusual during quality control that forms part of a feature that is probably inconsistent with real phenomena. [Not used]

4: Bad Value: An obviously erroneous data value. [Not used]

5: Changed Value: Data value adjusted during quality control. [Not used]

6: Value Below Detection Limit: The level of the measured phenomenon was too small to be quantified by the technique employed to measure it. The accompanying value is the detection limit for the technique or zero if that value is unknown. [Not used]

7: Value in Excess: The level of the measured phenomenon was too large to be quantified by the technique employed to measure it. The accompanying value is the measurement limit for the technique. [Not used]

8: Interpolated Value: This value has been derived by interpoloation from other values in the data object. [Not used]

9: Missing Value: The data value is missing. Any accompanying value will be a magic number representing absent data. [Any missing data reflect samples that were not analyzed or were analyzed but results are not (or not yet) reported; “nd” = “no data” used in these cases]

A: Value Phenomenon Uncertain: There is uncertainty in the description of the measured phenomenon associated with the value such as chemical species or biological entity.

BCO-DMO Processing Notes

Spaces within column headers were replaced with underscores
Special characters removed from column name (% changed to Percent)