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Metadata Report for BODC Series Reference Number 1761325


Metadata Summary

Data Description

Data Category Surface temp/sal
Instrument Type
NameCategories
WETLabs WETStar fluorometer  fluorometers
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
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Alex Forryan
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) OSMOSIS
 

Data Identifiers

Originator's Identifier JC090_PRODQXF_SURF
BODC Series Reference 1761325
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2013-09-01 00:00
End Time (yyyy-mm-dd hh:mm) 2013-09-14 23:59
Nominal Cycle Interval 30.0 seconds
 

Spatial Co-ordinates

Southernmost Latitude 42.60383 N ( 42° 36.2' N )
Northernmost Latitude 49.00200 N ( 49° 0.1' N )
Westernmost Longitude 16.35967 W ( 16° 21.6' W )
Easternmost Longitude 10.33417 W ( 10° 20.1' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 5.5 m
Maximum Sensor or Sampling Depth 5.5 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor or Sampling Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum -
 

Parameters

BODC CODERankUnitsTitle
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ALATGP011DegreesLatitude north relative to WGS84 by unspecified GPS system
ALONGP011DegreesLongitude east relative to WGS84 by unspecified GPS system
CNDCSG011Siemens per metreElectrical conductivity of the water body by thermosalinograph
CPHLUMTF1Milligrams per cubic metreConcentration 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
FVLTWS011VoltsRaw signal (voltage) of instrument output by linear-response chlorophyll fluorometer
POPTDR011PercentTransmittance (red light wavelength) per 25cm of the water body by 25cm path length red light transmissometer
PSALSG011DimensionlessPractical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and calibration against independent measurements
TEMPHU011Degrees CelsiusTemperature of the water body by thermosalinograph hull sensor and NO verification against independent measurements
TMESSG011Degrees CelsiusTemperature of electrical conductivity measurement by thermosalinograph
TVLTDR011VoltsRaw signal (voltage) of instrument output by 25cm path length red light transmissometer

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

OSMOSIS RRS James Cook JC090 Surface Hydrography Quality Report

The non-toxic was briefly off between 09:09:00 and 09:24:00 on 08/09/2013 for maintenance. BODC have flagged all channels associated to this for this time period including chlorophyll, fluorescence and transmittance.

BODC applied M flags to chlorophyll fluorescence and transmittance on 14/09/2013 10:27:00 - 10:29:00 due to a dip in transmittance.


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.

WET Labs WETStar Fluorometers

WET Labs WETStar fluorometers are miniature flow-through fluorometers, designed to measure relative concentrations of chlorophyll, CDOM, uranine, rhodamineWT dye, or phycoerythrin pigment in a sample of water. The sample is pumped through a quartz tube, and excited by a light source tuned to the fluorescence characteristics of the object substance. A photodiode detector measures the portion of the excitation energy that is emitted as fluorescence.

Specifications

By model:

  Chlorophyll WETStar CDOM WETStar Uranine WETStar Rhodamine WETStar Phycoerythrin WETStar
Excitation wavelength 460 nm 370 nm 485 nm 470 nm 525 nm
Emission wavelength 695 nm 460 nm 530 nm 590 nm 575 nm
Sensitivity 0.03 µg l-1 0.100 ppb QSD 1 µg l-1 - -
Range 0.03-75 µg l-1 0-100 ppb; 0-250 ppb 0-4000 µg l-1 - -

All models:

Temperature range 0-30°C
Depth rating 600 m
Response time 0.17 s analogue; 0.125 s digital
Output 0-5 VDC analogue; 0-4095 counts digital

Further details can be found in the manufacturer's specification sheet, and in the instrument manual.

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.

OSMOSIS RRS James Cook JC090 Surface Hydrography Instrumentation

The depth of seawater intake was at 5.5 m.

Manufacturer Model Serial number Last manufacturer's calibration date Comments
WETLabs WETStar WS3S-117 12/06/2013 -
WETLabs CSTAR CST-1132PR 19/7/2012 -
Sea-Bird SBE38 3854115-0490 12/12/2012 -
Sea-Bird SBE45 4548881-0230 27/11/2012 -

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:

  • Polled sampling: the instrument takes one sample on command
  • Autonomous sampling: the instrument samples at preprogrammed intervals and does not enter quiescence (sleep) state between samples
  • Serial Line Sync: a pulse on the serial line causes the instrument to wake up, sample and re-enter quiescent state automatically

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.

OSMOSIS RRS James Cook JC090 Surface Hydrography processing procedures

Originator's Data Processing

Data was extracted from TECHSAS SBE45-SBE45_JC1.TSG data stream each day and concatenated into a single file in time order. Time was converted from TECHSAS days to seconds from time origin (1/1/2013 0:0:0).

Conductivity was calibrated to bottle samples collected from the ship underway seawater inlet by calculating a time based correction factor = 2.4543E-9*time - 0.07596 which was added to the measured conductivity.

Files delivered to BODC

Filename Content description Format Interval Start date/time (UTC) E nd date/time (UTC) Comments
SBE45_SBE45_JC1_TSG SBE 45 and SBE 38 only Matlab 1 second 01/09/2013 08:47 14/09/2013 23:59 SBE 45 and SBE 38 data which is not delayed in time
Surf_JC_SM_JC1_SURFMETv2 All raw surfmet data Matlab <1 second 01/09/2013 12:37 14/09/2013 23:59 All sea surface hydrography data but the SBE45 and SBE 38 may be delayed in time.

BODC Data Processing

Files SBE45_SBE45_JC1_TSG and Surf_JC_SM_JC1_SURFMETv2 were selected for transfer into BODC format since they contained the most accurate version of sea surface hydrography data. The TSG (salinity, housing temperature and conductivity) and sea surface temperature data were sourced from the SBE45_SBE45_JC1_TSG data stream since the same variables in Surf_JC_SM_JC1_SURFMETv2 may be delayed in time.

The files were reformatted to NetCDF using BODC standard data banking procedures. The following table shows how variables within the file were mapped to appropriate BODC parameter codes:

SBE45_SBE45_JC1_TSG

Originator's variable Originator's units Description BODC Code BODC Units Unit conversion Comments
temp_h degrees C Temperature of conductivity measurement by thermosalinograph TMESSG01 degrees C    
conductivity S/m Electrical conductivity of the water body by thermosalinograph CNDCSG01 S/m    
salinity PSU Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and calibration against independent measurements PSALSG01 dimensionless    
temp_r degrees C Temperature of the water body by thermosalinograph hull sensor and NO verification against independent measurements TEMPHU01 degrees C    

Surf_JC_SM_JC1_SURFMETv2

Originator's variable Originator's units Description BODC Code BODC Units Unit conversion Comments
fluorescence volts Instrument output (voltage) by linear-response chlorophyll fluorometer FVLTWS01 volts    
transmittance volts Instrument output (voltage) by 25cm path length red light transmissometer TVLTDR01 volts    

Screening

All the reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag.

Calibration

Chlorophyll

CHL (µg L-1) = SF x (a - CWO)

where 'a' is the raw voltage output, the scale factor (SF) = 5.1 µg l-1 V-1 and the clean water offset (CWO) = 0.069 µg V-1 (1 µg L-1 = 1 mg m-3).

Transmittance

The following manufacturer's calibration was applied to the transmissometer to derive transmittance:

light transmission (%) = M x volts + B

where M = ( Tw / [W0 - Y0] ) * (A0 - Y0) / (A1 - Y1) = 21.7155266015201 and B = - M x Y1 = -1.302931596.

A0 = Vair = factory voltage output in air (manufacturer factory calibration)
A1 = Vair = current (most recent) voltage output in air
Y0 = Vd = factory dark or zero (blocked path) voltage (manufacturer factory calibration)
Y1 = Vd = current (most recent) dark or zero (blocked path) voltage
W0 = Vref = factory voltage output in pure water (manufacturer factory calibration)
Tw = % transmission in pure water = 100%
Vdark =0.060 V
Vair = 4.758 V
Vref = 4.665 V

Project Information

Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study (OSMOSIS)

Background

The Ocean Surface Mixing, Ocean Sub-mesoscale Interaction Study (OSMOSIS) consortium was funded to deliver NERC's Ocean Surface Boundary Layer (OSBL) programme. Commencing in 2011, this multiple year study will combine traditional observational techniques, such as moorings and CTDs, with the latest autonomous sampling technologies (including ocean gliders), capable of delivering near real-time scientific measurements through the water column.

The OSMOSIS consortium aims to improve understanding of the OSBL, the interface between the atmosphere and the deeper ocean. This layer of the water column is thought to play a pivotal role in global climate and the productivity of our oceans.

OSMOSIS involves collaborations between scientists at various universities (Reading, Oxford, Bangor, Southampton and East Anglia) together with researchers at the National Oceanography Centre (NOC), Scottish Association for Marine Science (SAMS) and Plymouth Marine Laboratory (PML). In addition, there are a number of project partners linked to the consortium.

Scientific Objectives

  • The primary goal of the fieldwork component of OSMOSIS is to obtain a year-long time series of the properties of the OSBL and its controlling 3D physical processes. This is achieved with an array of moorings (two nested clusters of 4 moorings, each centred around a central mooring) and gliders deployed near the Porcupine Abyssal Plain (PAP) observatory. Data obtained from this campaign will help with the understanding of these processes and subsequent development of associated parameterisations.
  • OSMOSIS will attempt to create parameterisations for the processes which determine the evolving stratification and potential vorticity budgets of the OSBL.
  • The overall legacy of OSMOSIS will be to develop new (physically based and observationally supported) parameterisations of processes that deepen and shoal the OSBL, and to implement and evaluate these parameterisations in a state-of-the-art global coupled climate model, facilitating improved weather and climate predictions.

Fieldwork

Three cruises are directly associated with the OSMOSIS consortium. Preliminary exploratory work in the Clyde Sea (September 2011) to hone techniques and strategies, followed by a mooring deployment and recovery cruise in the vicinity of the Porcupine Abyssal Plain (PAP) observatory (in late Summer 2012 and 2013 respectively). Additional opportunist ship time being factored in to support the ambitious glider operations associated with OSMOSIS.

Instrumentation

Types of instrumentation and measurements associated with the OSMOSIS observational campaign:

  • Ocean gliders
  • Wave rider buoys
  • Towed SeaSoar surveys
  • Microshear measurements
  • Moored current meters, conductivity-temperature sensors and ADCPs
  • Traditional shipboard measurements (including CTD, underway, discrete nutrients, LADCP, ADCP).

Contacts

Collaborator Organisation
Prof. Stephen Belcher University of Reading, U.K
Dr. Alberto C Naveira Garabato University of Southampton, U.K

Data Activity or Cruise Information

Cruise

Cruise Name JC090
Departure Date 2013-08-31
Arrival Date 2013-09-16
Principal Scientist(s)Alberto C Naveira Garabato (University of Southampton School of Ocean and Earth Science)
Ship RRS James Cook

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
B nominal value
Q value below limit of quantification