Dataset: GT10 - Spctrl_Absp
Deployment: KN199-04

For sample processing information and methodology, see associated Supplemental File, "SeaBASS documentation" (SeaBASS_NDFilter.pdf).

BCO-DMO Processing notes:
Edits made:
- Parameter header names were edited to conform to BCO-dMO convention
- Blank data fields were edited to 'nd'
- Edited time to remove colons and drop unused seconds
- Edited precision of lat/lon to four decimals.
- Edited precision of absorbance, and respecctive absorbance standard deviation and absorption coefficient data to 8 decimals.
- Added columns for 'diameter' and 'volume_filtered' (previously in metadata log file)
- Removed the comment information from file headers. Where necessary the information was incorporated into BCO-DMO metadata fields and retained entirely in Dataset Description.

Note: The variable "abs_blank_sd" corresponds to standard deviation data for station 7 only, when sample processing spanned two days (abs_blank_sd was calculated at the end of each day). This parameter is displayed as 'nd' for all other stations where all processing was completed in one day.

Definitions of parameter name components obtained from PI:

• ap=total particulate absorption
• ad= detrital absorption
• aph= phytoplankton absorption
• ap-ad=aph

Correspondence with the Co-PI on 2013.01.12, necessitated editing the header note indicating NASA's pump. Therefore, this comment retained in the header has been edited to the following text:

# samples from station 1 were collected with WHOI's GEOTRACES pump
# sample numbers for stations greater than 1 were collected with NASA's
# surface peristaltic pump

Additional GEOTRACES Processing: After the data were submitted to the International Data Management Office, BODC, the office noticed that important identifying information was missing in many datasets. With the agreement of BODC and the US GEOTRACES lead PIs, BCO-DMO added standard US GEOTRACES information, such as the US GEOTRACES event number, to each submitted dataset lacking this information. To accomplish this, BCO-DMO compiled a 'master' dataset composed of the following parameters: station_GEOTRC, cast_GEOTRC (bottle and pump data only), event_GEOTRC, sample_GEOTRC, sample_bottle_GEOTRC (bottle data only), bottle_GEOTRC (bottle data only), depth_GEOTRC_CTD (bottle data only), depth_GEOTRC_CTD_rounded (bottle data only), BTL_ISO_DateTime_UTC (bottle data only), and GeoFish_id (GeoFish data only). This added information will facilitate subsequent analysis and inter comparison of the datasets.

Bottle parameters in the master file were taken from the GT-C_Bottle_GT10, GT-C_Bottle_GT11, ODF_Bottle_GT10, and ODF_Bottle_GT11 datasets. Non-bottle parameters, including those from GeoFish tows, Aerosol sampling, and McLane Pumps, were taken from the Event_Log_GT10 and Event_Log_GT11 datasets. McLane pump cast numbers missing in event logs were taken from the Particulate Th-234 dataset submitted by Ken Buesseler.

A standardized BCO-DMO method (called “join”) was then used to merge the missing parameters to each US GEOTRACES dataset, most often by matching on sample_GEOTRC or on some unique combination of other parameters.

If the master parameters were included in the original data file and the values did not differ from the master file, the original data columns were retained and the name of the parameters were changed from the PI-submitted names to the standardized master names. If there were differences between the PI-supplied parameter values and those in the master file, both columns were retained. If the original data submission included all of the master parameters, no additional columns were added, but parameter names were modified to match the naming conventions of the master file.

See the dataset parameters documentation for a description of which parameters were supplied by the PI and which were added via the join method.