Extended Ellett Line Inorganic Nutrient Data for RRS Discovery cruise D312
Originator's Data Acquisition and Analysis
Inorganic nutrients were measured on every bottle from every CTD cast following Sanders and Jickells (2000) using a Skalar San Plus autoanalyser equipped equipped with an all glass phosphate line. All data was processed in flow access version 1.04.4. In total 634 niskin bottle were analysed. Samples were drawn directly from niskin bottles into 25 ml sterilin polystyrene coulter counter vials, refrigerated in the dark at 4°C and analysed within 24 hours. Overall seventeen runs were carried out.
The instrument did not perform well on this trip despite the usual precautions being taken (washing the lines with 10 % Decon (N, Si) or Sodium Hydroxide (P), changing the tubes). Despite the various problems encountered all samples were analysed satisfactorily with the exception of phosphate from station 152.
BODC processing
The data were received in 64 pstar files which were loaded into the BODC database using established BODC data banking procedures without any changes.
The mapping between the originator's channels and BODC parameter codes is detailed in the table below.
| Originator's Parameter | Unit | Description | BODC Parameter Code | BODC Unit | Comments |
|---|---|---|---|---|---|
| NO3+NO2 | Micromoles per litre | Concentration of Nitrate + Nitrite {NO3+NO2} | NTRZAATX | Micromoles per litre | n/a |
| PO4 | Micromoles per litre | Concentration of Phosphate {PO4} | PHOSAATX | Micromoles per litre | n/a |
| SiO4 | Micromoles per litre | Concentration of Silicate | SLCAAATX | Micromoles per litre | n/a |
Data Quality Report
For a detailed QC analysis please see ( Cruise Report ) page 106.
