Metadata Report for BODC Series Reference Number 1337892


Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
NameCategories
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Prof Richard Sanders
Originating Organization Southampton Oceanography Centre (now National Oceanography Centre, Southampton)
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier DI253_CTD_NUTS_208:14055
BODC Series Reference 1337892
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2001-05-23 11:04
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -
 

Spatial Co-ordinates

Latitude 61.00080 N ( 61° 0.0' N )
Longitude 11.63760 W ( 11° 38.3' W )
Positional Uncertainty Unspecified
Minimum Sensor Depth 7.0 m
Maximum Sensor Depth 1079.0 m
Minimum Sensor Height 11.5 m
Maximum Sensor Height 1083.5 m
Sea Floor Depth 1090.5 m
Sensor Distribution Unspecified -
Sensor Depth Datum Unspecified -
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
ADEPZZ01 1 Metres DepBelowSurf Depth below surface of the water body
BOTTFLAG 1 Dimensionless C22_flag Sampling process quality flag (BODC C22)
NTRZAATX 1 Micromoles per litre NO3+NO2_Unfilt_ColAA Concentration of nitrate+nitrite {NO3+NO2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
PHOSAATX 1 Micromoles per litre PO4_Unfilt_ColAA Concentration of phosphate {PO43- CAS 14265-44-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
ROSPOSID 1 Dimensionless RosPos Bottle rosette position identifier
SAMPRFNM 1 Dimensionless SampRef Sample reference number
SLCAAATX 1 Micromoles per litre SiOx_Unfilt_ColAA Concentration of silicate {SiO44- CAS 17181-37-2} per unit volume of the water body [dissolved plus reactive particulate phase] by colorimetric autoanalysis
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database


Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."


Narrative Documents

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles have a capacity between 1.7 and 30 L, while Lever Action bottles have a capacity between 1.7 and 12 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

CTD bottle samples of nutrients, TDN and DOC collected on cruise D253 along Extended Ellett Line

Originator's Protocol for Data Acquisition and Analysis

A large scale CTD survey of the Iceland Basin and Rockall Trough was carried out during this cruise along the Extended Ellett Line, comprising a total of 153 CTD casts.

To determine nutrients, samples were drawn from all depths at all stations, with the exception of stations 14024, 14025 and 14026, directly into virgin polystyrene coulter counter vials. Samples were then stored in a fridge before analysis, which was generally commenced within 12 hours. The concentrations of nitrate + nitrite, phosphate and silicate were then determined using conventional colorimetric methods using a Skalar San Plus autoanalyser. Further details are in Allen (2001), pages 146 to 153.

TDN (Total Dissolved Nitrogen) and DOC (Dissolved Organic Carbon) were determined by high temperature oxidation- further details on pages 170 to 171 of Allen (2001).

References Cited

Allen, J. T. 2001. RRS Discovery cruise 253 04 May - 20 Jun 2001 . Faeroes, Iceland, Scotland Hydrographic and Environemental Survey (FISHES). Southampton Oceanography Centre Cruise Report, No 37, 206pp.

Instrumentation Description

The samples were taken with a CTD frame with 24 position rosette and 24 Niskin bottles. Nutrients were analysed with a Skalar San Plus autoanalyser.

BODC Data Processing Procedures

Data were received at BODC in the form of pstar format sample files, and various spreadsheets containing nutrient, chl-a, TDN and DOC measurements. Bottle metadata were derived from the pstar files as these recorded rosette position and pressure, whereas some spreadsheets only recorded the nominal depths of bottle firing. Having combined the two data sources, the data were loaded into the BODC database using established BODC data banking procedures.

Where no pressure or depth information could be found from any source, a small number of bottles and measurements from them were discarded.

Parameters from the originator's source files were mapped to BODC parameter codes as follows:

Originator's Parameter Unit Description BODC Parameter Code BODC Unit Comments
no2+3 µmol/l Nitrate and nitrate from bottle sample determined by Auto Analyzer NTRZAATX Micromoles per litre n/a
sio3 µmol/l Silicate from bottle sample determined by Auto Analyzer SLCAAATX Micromoles per litre n/a
po4 µmol/l Phosphate from bottle sample determined by Auto Analyzer PHOSAATX Micromoles per litre n/a
TDN Total Dissolved Nitrogen mM TDN from bottle sample determined by high temperature oxidation NTOTCOD1 Micromoles per litre n/a
DOC Disslved Organic carbon mM DOC from bottle sample determined by high temperature oxidation CORGCOF1 Micromoles per litre n/a

Data Quality Report

No report provided by the originator, but information about data quality is included in Allen (2001).

Problem Report

No problem report.

bindepth m Depth of ADCP bin DBINAA01 m -
evelcal cm s -1 Relative Eastward current velocity LCEWAS01 cm s -1 Not in final file as absolute velocities are present
nvelcal cm s -1 Relative Northward current velocity LCNSAS01 cm s -1 Not in final file as absolute velocities are present
velvert cm s -1 Vertical current velocity LRZAAS01 cm s -1 -
velerr cm s -1 Velocity error LERRAS01 cm s -1 -
intense1 db Beam 1 intensity ASAMSP00 db -
intense2 db Beam 2 intensity ASAMSP02 db -
intense3 db Beam 3 intensity ASAMSP03 db -
intense4 db Beam 4 intensity ASAMSP04 db -
ve cm s -1 Ship's Eastward velocity APEWGP01 cm s -1 -
vn cm s -1 Ship's Northward velocity APNSGP01 cm s -1 -
absve cm s -1 Absolute Eastward current velocity LCEWAS01 cm s -1 -
absvn cm s -1 Absolute Northward current velocity LCNSAS01 cm s -1 -
lat Degrees Latitude ALATGP01 Degrees -
lon Degrees Longitude ALONGP01 Degrees -
distrun km Distance run DSRNCV01 km -

Reformatted data were visually checked using the in-house editor EDSERPLO. No data values were edited or deleted. Flagging was achieved by modification of the associated quality control flag to 'M' for suspect values and 'N' for nulls.

Once quality control screening was complete, the data were archived in the BODC National Oceanographic Database and the associated metadata were loaded into an ORACLE Relational Database Management System.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2001-05-23
End Date (yyyy-mm-dd) 2001-05-23
Organization Undertaking ActivitySouthampton Oceanography Centre (now National Oceanography Centre, Southampton)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierDI253_CTD_14055
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for DI253_CTD_14055

Sample reference number Nominal collection volume(l) Bottle rosette position Bottle firing sequence number Minimum pressure sampled (dbar) Maximum pressure sampled (dbar) Depth of sampling point (m) Bottle type Sample quality flag Bottle reference Comments
897728   1   1091.70 1092.70 1079.00 Niskin bottle No problem reported    
897731   2   1001.90 1002.90  990.50 Niskin bottle No problem reported    
897734   3    800.30  801.30  791.70 Niskin bottle No problem reported    
897737   4    601.10  602.10  595.00 Niskin bottle No problem reported    
897740   5    499.90  500.90  495.00 Niskin bottle No problem reported    
897743   6    400.00  401.00  396.30 Niskin bottle No problem reported    
897746   7    300.30  301.30  297.70 Niskin bottle No problem reported    
897749   8    201.30  202.30  199.80 Niskin bottle No problem reported    
897752   9    151.60  152.60  150.60 Niskin bottle No problem reported    
897755   10    101.60  102.60  101.10 Niskin bottle No problem reported    
897758   11     76.50   77.50   76.30 Niskin bottle No problem reported    
897761   12     51.60   52.60   51.60 Niskin bottle No problem reported    
897764   13     27.00   28.00   27.20 Niskin bottle No problem reported    
897767   14      6.60    7.60    7.00 Niskin bottle No problem reported    

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.

Cruise

Cruise Name D253
Departure Date 2001-05-04
Arrival Date 2001-06-20
Principal Scientist(s)John T Allen (Southampton Oceanography Centre)
Ship RRS Discovery

Complete Cruise Metadata Report is available here


Fixed Station Information


No Fixed Station Information held for the Series


BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain