Metadata Report for BODC Series Reference Number 1762353


Metadata Summary

Data Description

Data Category Surface temp/sal
Instrument Type
NameCategories
WETLabs C-Star transmissometer  transmissometers
Sea-Bird SBE 45 MicroTSG thermosalinograph  thermosalinographs; water temperature sensor; salinity sensor
Sea-Bird SBE 38 thermometer  water temperature sensor
Turner 10-AU chlorophyll field fluorometer  fluorometers
Litre Meter flow meter  flow meters
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Rob Thomas
Originating Organization British Oceanographic Data Centre, Liverpool
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier JR20140922_PRODQXF_SURF
BODC Series Reference 1762353
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2014-09-22 20:10
End Time (yyyy-mm-dd hh:mm) 2014-11-02 13:01
Nominal Cycle Interval 60.0 seconds
 

Spatial Co-ordinates

Southernmost Latitude 51.69167 S ( 51° 41.5' S )
Northernmost Latitude 53.63400 N ( 53° 38.0' N )
Westernmost Longitude 57.83000 W ( 57° 49.8' W )
Easternmost Longitude 1.93000 E ( 1° 55.8' E )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 6.5 m
Maximum Sensor Depth 6.5 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum -
 

Parameters

BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
CNDCSG01 1 Siemens per metre TSG_Cond Electrical conductivity of the water body by thermosalinograph
CPHLUMTF 1 Milligrams per cubic metre chl-a_water_NTTFfluor_manufctrcal Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >unknown phase] by through-flow fluorometer plumbed into non-toxic supply and manufacturer's calibration applied
INFLTF01 1 Litres per minute TSG+Fl_Flow Flow rate through instrument
POPTDR01 1 Percent Trans_Red_25cm Transmittance (red light wavelength) per 25cm of the water body by 25cm path length red light transmissometer
PSALSG01 1 Dimensionless P_sal_TSG_calib Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and calibration against independent measurements
SVELSG01 1 Metres per second TSG_Sound_Vel Sound velocity in the water body by thermosalinograph and computation from temperature and salinity by unspecified algorithm
TEMPHG01 1 Degrees Celsius CalTSGHullTmp Temperature of the water body by thermosalinograph hull sensor and verification against independent measurements
TMESSG01 1 Degrees Celsius TSG_Meas_Temp Temperature of conductivity measurement by thermosalinograph
 

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

Fluorescence

The chlorophyll sensor for the underway system is considered suspect and care should be taken when using these data.

RRS James Clark Ross Cruise AMT24 (JR20140922) Surface Hydrography Data Quality Document

For all hydrogrpahy channels data were flagged before the underway system was turned on and after it was turned off. Obvious spikes were flagged suspect for TEMPHU01, PSALSU01 and CPHLUMTF.


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

SeaBird Digital Oceanographic Thermometer SBE38

The SBE38 is an ultra-stable thermistor that can be integrated as a remote temperature sensor with an SBE21 Thermosalinograph or an SBE 45 Micro TSG, or as a secondary temperature sensor with an SBE 16 plus, 16plus-IM, 16plus V2, 16plus-IM V2 or 19plus V2 SEACAT CTD.

Temperature is determined by applying an AC excitation to reference resistances and an ultra-stable aged thermistor. The reference resistor is a hermetically sealed VISHAY. AC excitation and ratiometric comparison using a common processing channel removes measurement errors due to parasitic thermocouples, offset voltages, leakage currents and gain errors.

The SBE38 can operate in polled sampling, where it takes one sample and transmits the data, or in continuous sampling.

Specifications

Depth rating up to 10500 m
Temperature range -5 to 35°C
Initial accuracy ± 0.001°C
Resolution 0.00025°C
Stability 0.001°C in 6 months
Response time 500 ms
Self-heating error < 200 µK

Further details can be found in the manufacturer's specification sheet .

Turner Designs 10AU Field Fluorometer

The Turner Designs 10AU is designed for continuous-flow monitoring or discrete sample analyses of fluorescent species. A variety of optical kits with appropriate filters and lamps are available for a wide range of applications. Individual filters and lamps are also available for customised applications.

Standard optical kits include those for chlorophyll- a (extracted and/or in vivo ), phycocyanin, phycoerythrin, CDOM, ammonium, rhodamine and fluorescein dye tracing, crude oil, refined oil, histamine and optical brighteners.

The instrument's light source is a 4 watt lamp and the detector is a photomultiplier tube with a standard detection range of 300-650 nm. A red-sensitive version with a detetion range of 185-970 nm is also available.

Specifications

Operating temperature 0 to 55°C
Detector PhotoMultiplier Tube

300 to 650 nm (standard)

185 to 870 nm (Red)

Detection Limits:
Extracted Chlorophyll- a
Rhodamine WT Dye
Fluorescein Dye

0.025 µg L -1
0.01 ppb (in potable water)
0.01 ppb (in potable water)
Linear range:
Extracted Chlorophyll- a
Rhodamine WT Dye
Fluorescein Dye

0 to 250µg L -1
0 to 250 ppb
0 to 250 ppb

Further details can be found in the manufacturer's specification sheet .

WETLabs C-Star transmissometer

This instrument is designed to measure beam transmittance by submersion or with an optional flow tube for pumped applications. It can be used in profiles, moorings or as part of an underway system.

Two models are available, a 25 cm pathlength, which can be built in aluminum or co-polymer, and a 10 cm pathlength with a plastic housing. Both have an analog output, but a digital model is also available.

This instrument has been updated to provide a high resolution RS232 data output, while maintaining the same design and characteristics.

Specifications

Pathlength 10 or 25 cm
Wavelength 370, 470, 530 or 660 nm
Bandwidth

~ 20 nm for wavelengths of 470, 530 and 660 nm

~ 10 to 12 nm for a wavelength of 370 nm

Temperature error 0.02 % full scale °C -1
Temperature range 0 to 30°C
Rated depth

600 m (plastic housing)

6000 m (aluminum housing)

Further details are available in the manufacturer's specification sheet or user guide .

Litre Meter flow meter

A flow meter used to monitor water flow rates for pumped systems such as ships' continuous seawater supplies.

RRS James Clark Ross Cruise AMT24 (JR20140922) Surface Hydrography Instrument Description Document

Instrumentation

Manufacturer Model Main function Serial Number Calibration Date
Seatex Seapath 320+ Position (Latitude and Longitude) - -
Sea Bird Electronics SBE 45 Temperature/Salinity of the water body 0130 14/05/2014
Sea Bird Electronics SBE 38 Temperature 0771 17/03/2014
Sea Bird electronics SBE 38 Temperature - -
Chelsea Technologies 10 AU005 Fluorometer - -
Wet Labs C-Star Transmittance CST-1279DR 07/09/2014
Litre Meter 05SPFA40CE Flow rate 05/811950 09/06/2011

SeaBird MicroTSG Thermosalinograph SBE 45

The SBE45 MicroTSG is an externally powered instrument designed for shipboard measurement of temperature and conductivity of pumped near-surface water samples. The instrument can also compute salinity and sound velocity internally.

The MicroTSG comprises a platinum-electrode glass conductivity cell and a stable, pressure-protected thermistor temperature sensor. It also contains an RS-232 port for appending the output of a remote temperature sensor, allowing for direct measurement of sea surface temperature.

The instrument can operate in Polled, Autonomous and Serial Line Sync sampling modes:

Specifications

  Conductivity Temperature Salinity
Range 0 to 7 Sm -1 -5 to 35°C  
Initial accuracy 0.0003 Sm -1 0.002°C 0.005 (typical)
Resolution 0.00001 Sm -1 0.0001°C 0.0002 (typical)
Typical stability (per month) 0.0003 Sm -1 0.0002°C 0.003 (typical)

Further details can be found in the manufacturer's specification sheet .

RRS James Clark Ross Cruise AMT24 (JR20140922) Surface Hydrography Processing Document

Originator's Data Processing

The sea surface hydrography measurements were performed by a Sea Bird electronics thermosalinograph in the ship's flow through system and by a temperature sensor located near the flow through intake, at the hull. The depth of the flow through intake was 6.5 m. The data streams were logged every second to the SCS system and merged into a comma separated file format (.ACO), and the header information was stored in .TPL files.

The surface hydrography data were also logged to the oceanlogger.ACO file.

Filename Content Description Format Interval Start Date Start Time End Date End Time
seatex-gga.ACO Latitude and Longitude ASCII (.ACO) 1 Hz 11/09/2014 12:37:39 02/11/2014 15:47:52
oceanlogger.ACO Temperature Housing ASCII (.ACO) ~1 Hz 18/09/2014 14:33:25 02/11/2014 15:47:00
Temperature Hull Sensor x2
Transmissometer
Conductivity
Salinity
Fluorometer
Sound velocity
Flow Meter

BODC Data Processing

Sea surface hydrography parameters were transferred to internal BODC format and matched against BODC parameter codes, as presented in the table below. No unit conversions were applied, as the originators units were equivalent to the units of the respective BODC parameter code units assigned. BODC processing procedures included loading of data and reduction through averaging, unit conversions, visual screening and flagging of anomalous values. files were averaged to 60 second intervals.

Originator's File Originator's Parameter Originator's Units Description BODC parameter code BODC units Comments and unit conversions
seatex-gga.ACO lat Degrees (+ve N) Latitude north (WGS84) by Seatex Seapath DGPS ALATGP01 Degrees (+ve N) -
seatex-gga.ACO lon Degrees (+ve E) Longitude east (WGS84) by Seatex Seapath DGPS ALONGP01 Degrees (+ve N) -
oceanlogger.ACO salinity psu Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and NO calibration against independent measurements. PSALSU01 Dimensionless
- - - Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and calibration against independent measurements PSALSG01 Dimensionless BODC calibrated salinity. ICALRF 7936
oceanlogger.ACO sstemp °C Temperature of the water body by thermosalinograph hull sensor and NO verification against independent measurements TEMPHU01 Degrees Celsius -
Temperature of the water body by thermosalinograph hull sensor and verification against independent measurements TEMPHG01 Degrees Celsius BODC calibrated temperature. ICALRF 7937-
oceanlogger.ACO sstemp2 °C Temperature of the water body by thermosalinograph hull sensor (second sensor) and NO verification against independent measurements TEMPHU02 Degrees Celsius Parameter used as a second sensor
oceanlogger.ACO tstemp °C Temperature of conductivity measurement by thermosalinograph TMESSG01 Degrees Celsius -
oceanlogger.ACO conductivity S m -1 Electrical conductivity of the water body by in-situ conductivity cell CNDCSG01 Siemens per metre -
oceanlogger.ACO sound_velocity m s -1 Sound velocity in the water body by thermosalinograph and computation from temperature and salinity by unspecified algorithm SVELSG01 Metres per second -
oceanlogger.ACO chlorophyll µg L -1 Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate phase] by through-flow fluorometer plumbed into non-toxic supply and manufacturer's calibration applied CPHLUMTF mg m -3 -
oceanlogger.ACO trans 0< Tr <1 Transmittance POPTDR01 Percent * 100
oceanlogger.ACO flowrate l/min Flow rate through instrument INFLTF01 L min -1 -

Sample Calibrations

Temperature

The hull temperature sensor data were calibrated against the CTD temperature sensors during the cruise. The data from the hull sensor were compared with the temperature from the average of two externally mounted CTD temperature sensors at 6 decibars at corresponding measurement times. The temperature offset (CTD - Hull) were plotted against cruise day and CTD sensor temperature to identify and remove outliers. A regression analysis was run on the remaining data points and revealed a weak and insignificant relationship between the offset and CTD sensor data (R 2 = 0.0281; n = 65; p = 0.1819). A weak but significant relationship was found between offset and cruise time (R 2 = 0.18997; n = 65; p = 0.0003).

Due to the significance between the offset and cruise time the following offset was applied to the Hull temperature sensor:

BODC ICALRF 7937 TEMPHG01 = 1.0034 * TEMPHU01 - 0.1069

Salinity

Bench salinometer discrete surface samples (at least 3 per day) collected from the non-toxic underway system during the cruise were used to create a calibration dataset for the calibration of the SBE45 TSG salinity data. The offset between the bench salinity and TSG salinity was calculated and plotted against bench salinity to identify outliers. There was a significant regression of the offset with bench salinity measurement (n = 86; R 2 = 0.241; p < 0.001).

BODC ICALRF 7936 PSALSG01 = 0.9978 * PSALSU01 + 0.0588

Fluorometer

Although discrete chlorophyll samples were collected from the ship's underway system. Fluorometer values were considered unreliable. No calibration has been applied.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name JR20140922 (AMT24, JR303)
Departure Date 2014-09-22
Arrival Date 2014-11-01
Principal Scientist(s)Tim Smyth (Plymouth Marine Laboratory)
Ship RRS James Clark Ross

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