Dataset: Southern Ocean Silicate
Deployment: IN2023_V04

Programmable Flow Injection (pFI) silicate underway data

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/931760

Principal Investigator:

Maxime Grand (Moss Landing Marine Laboratories, MLML)

Contact:

Maxime Grand (Moss Landing Marine Laboratories, MLML)

BCO-DMO Data Manager:

Sawyer Newman (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Collaborative Research: Developing Automated Nutrient and Trace Metal Methodology using Programmable Flow Injection (pFI-SI-LOV)

Version:

Deployment Synonyms:

INIV

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Description

Methods & Sampling

Dataset acquisition description

Unfiltered seawater samples from the RV Investigator underway lab were aspirated using an auxiliary diaphragm pump (KNF, USA) into a 3 mL sample loop every 15-30 min during the deployment. The stored samples were immediately analyzed for silicate in duplicate using the pFI assay protocol outlined in Hatta et al. (2021). One key modification was adjusting the holding coils’ temperatures to 25ºC instead of the originally specified 50ºC. In tandem with this temperature change, the stop flow time in the flow cell was extended to 60 seconds to ensure the absorbance of the silicomolybdenum blue at 660 nm product reached a steady state.

Data Processing Description

Dataset Processing Description

The FloZF software returns a time stamped mean absorbance at 660 nm calculated from the last 10 seconds of the 60 sec stopped flow time in the pFI flow cell. Corresponding silicate concentrations were calculated using the slopes and intercepts of calibrations obtained every 12 hours during this deployment. All samples were measured in duplicate and the mean silicate concentration is reported here.

Quality flags represented in the primary data file

1 = good
2 = bad
3 = below limit of detection
9 = not sampled

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1924539	NSF Division of Ocean Sciences

Instruments

None available yet

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Time_UTC	Sample date and time in UTC.	unitless	DateTime
Latitude	Sample latitude in decimal degrees; a positive value indicates a Northern coordinate.	decimal degrees	lat
Longitude	Sample longitude in decimal degrees; a negative value indicates a Western coordinate.	decimal degrees	lon
Mean_pFI_Si_OH_4_concentration	Mean silicate (pFI Si(OH)4) concentration from duplicate sample analysis.	umol/L	Silicate
mean_pFI_flag	Data quality flag for mean silicate value. 1 = good, 2 = bad, 3 = below limit of detection, 9 = not sampled.	unitless	qflag
Depth	Sample depth.	meters (m)	depth

Database

Contribute Data

Dataset: Southern Ocean Silicate
Deployment: IN2023_V04

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Southern Ocean SilicateDeployment: IN2023_V04

Dataset acquisition description

Dataset Processing Description

Dataset: Southern Ocean Silicate
Deployment: IN2023_V04