AMT16 CTD rosette sampled Particulate Inorganic Carbon (PIC) and Biological Silica (BSi)
Data Acquisition and Analysis
This data originates from analyses on samples collected from CTD casts during the AMT16 cruise. Samples were taken from 6 main light depths from the pre-dawn CTD cast (~0200 - 0400h local time) and from the late morning 'optics' cast (1100h local time). PIC was collected from 1 litre of seawater by vacuum filtration onto a 0.45 µm cellulose nitrate filter. The filters were then rinsed with potassium tetraborate buffer and stored in individual cryo vials at room temperature for the remainder of the cruise. BSi was collected from 1 litre of seawater by vacuum filtration onto a 0.4 µm polycarbonate filter, which were then stored in scintillation vials at -20 o C for the duration of the cruise.
PIC: After the cruise the samples were analysed using inductively coupled plasma atomic emission spectrometry (ICPAES).
BSi: After the cruise the residue on the filter paper was dissolved in 2.5 ml sodium hydroxide and then the solution was neutralised with 0.1 mol L -1 hydrochloric acid and the Si concentration was measured using a flow autoanalyser.
References Cited
Poulton A.J., Adey T.R., Balch W.M., and Holligan P., 2007. Relating coccolithophore calcification rates to phytoplankton community dynamics: regional differences and implications for carbon export. Deep-Sea Research Part II, 54(5-7), 538-557.
Instrumentation Description
Not relevant to this dataset.
BODC Data Processing Procedures
Data were submitted to BODC in a tab delimited text format and saved to the BODC archive with reference BGL060512. Sample metadata were checked against information held in the database. There were no discrepancies in the metadata provided.
Parameter codes defined in the BODC parameter dictionary were assigned to the variables. The PIC data were converted from mg m -3 to µmol L -1 by dividing by 12. The BSi data were provided in units (mmol m -3 ) equivalent with those used in the BODC database for the appropriate parameter code.
Data loaded into BODC's database with only a unit conversion change applied.
A parameter mapping table is provided below;
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| PIC | mg m -3 | Concentration of carbon (inorganic) {PIC} per unit volume of the water body [particulate >0.4µm phase] by filtration, acid digestion and inductively-coupled plasma atomic emission spectroscopy | CINGFA04 | µmol l -1 | Unit conversion of x1/12 applied to data |
| BSi | mmol m -3 | Concentration of biogenic silica {opal} per unit volume of the water body [particulate >0.4µm phase] by filtration, alkali hydrolysis and colorimetric analysis | OPALWCP4 | µmol l -1 | n/a |
Data Quality Report
BODC were not advised of specific quality checks carried out by the data originators. There were no standout values in the sample data provided to BODC.
Problem Report
Not relevant to this dataset.
