Data have been corrected for field and analytical blank. All reported trace element concentration values have been normalized to the volume of air filtered during that sample collection. Each sample collection period (n = 17) produced 36 replicate filters. Three of those filters were digested with concentrated ultrapure nitric and hydrofluoric acids to produce three replicate measurements. In the majority of cases, the three replicates were above the field blank value and agreed well. Data from the three replicates were averaged and reported along with the standard deviation. Outliers and replicate samples that were below the field blank value were not included in the mean. Data are marked as described in the datasheet. 

Quality flag codes:
Codes follow the SeaDataNet scheme (https://www.geotraces.org/geotraces-quality-flag-policy/)
BDL = below detection limit;
0 = No QC performed;
1 = Good data;
2 = Probably good data;
3 = Probably bad data that is potentially correctable;
4 = Bad data;
5 = Value changed;
6 = Sample < blank;
8 = Interpolated value;
​9 = Missing value.

BCO-DMO Processing:
- modified parameter names to conform with BCO-DMO naming conventions;
- replaced missing data values of -999 and -9999 with "nd";
- added date-time columns in ISO8601 format.

Version History:
26 May 2020 (current version) - replaced entire dataset using GEOTRACES DOoR format.
12 Jul 2017 - replaced entire dataset. The previous version used the wrong volume of air to normalize the data.
23 Jan 2017 - original version.