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Metadata Report for BODC Series Reference Number 747334

Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags

Metadata Summary

Data Description

Data Category

Water column chemistry

Instrument Type

Name	Categories
Aanderaa Oxygen Optode 3835	dissolved gas sensors

Instrument Mounting

moored surface buoy

Originating Country

United Kingdom

Originator

Originating Organization

Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory

Processing Status

banked

Project(s)

Coastal Observatory

Data Identifiers

Originator's Identifier	LB_38_OXY127
BODC Series Reference	747334

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm)	2006-12-15 10:00
End Time (yyyy-mm-dd hh:mm)	2007-02-14 13:00
Nominal Cycle Interval	1800.0 seconds

Spatial Co-ordinates

Latitude	53.53320 N ( 53° 32.0' N )
Longitude	3.36070 W ( 3° 21.6' W )
Positional Uncertainty	0.1 to 0.5 n.miles
Minimum Sensor Depth	1.0 m
Maximum Sensor Depth	1.0 m
Minimum Sensor Height	23.4 m
Maximum Sensor Height	23.4 m
Sea Floor Depth	24.4 m
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	Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum	Instantaneous - Depth measured below water line or instantaneous water body surface

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)
ACYCAA01	1	Dimensionless	Record_No	Sequence number
DOXYOP01	1	Micromoles per litre	WC_dissO2_ISoptode	Concentration of oxygen {O2 CAS 7782-44-7} per unit volume of the water body [dissolved plus reactive particulate phase] by in-situ oxygen optode
OXYSOP01	1	Percent	Optode_O2Sat	Saturation of oxygen {O2 CAS 7782-44-7} in the water body [dissolved plus reactive particulate phase] by in-situ oxygen optode and computation from concentration

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

Aanderaa Oxygen Optodes models 3835, 4130, 4175, 3830, 3930 and 3975

The Aanderaa Oxygen Optode is based on the ability of selected substances to act as dynamic fluorescence quenchers. The fluorescent indicator is a special platinum porphyrin complex embedded in a gas permeable foil that is exposed to the surrounding water.

A black optical isolation coating protects the complex from sunlight and fluorescent particles in the water. This sensing foil is attached to a window providing optical access for the measuring system from inside a watertight titanium housing.

The foil is excited by modulated blue light, and the phase of a returned red light is measured. By linearizing and temperature compensating, with an incorporated temperature sensor, the absolute O ₂ concentration can be determined. According to the manufacturer, the lifetime-based luminescence quenching principle offers the following advantages over electro-chemical sensors:

Not stirring sensitive (it consumes no oxygen)
Less affected by fouling
Measures absolute oxygen concentrations without repeated calibrations
Better long-term stability
Less affected by pressure
Pressure behaviour is predictable
Faster response time

The 3835, 4130 and 4175 models are designed to operate down to 300 m, while there are two versions of the 3830, 3930 and 3975 models, designed to operate down to 2000 m and 6000 m, respectively. The sensors fit directly on to the top end-plate of Recording Current Meter RCM 9, and other Aanderaa instruments. Sensor specifications may be viewed via the following links: Aanderaa Oxygen Optodes 3835/4130/4175 and Aanderaa Oxygen Optodes 3830/3930/3975 .

Cefas SmartBuoy data processing

This document outlines the procedures in place at Cefas in August 2005 for processing and quality assuring SmartBuoy data.

Raw data files are processed and the data move through 4 levels, starting with raw data at level 0 through to level 3, where data are fully quality-assured and expressed in appropriate units. The application of the procedures at each level result in data deemed fit to progress to the next level.

Cefas Quality Assurance (QA) Protocols

At Level 0, raw binary data files from the loggers are transferred to the network.

Automated checks - Level 1

Level 1 involves applying automated quality assurance procedures to the data. These include the following steps:

Burst data are loaded into memory for processing.
Calibration data for all instruments and sensors used on the deployment are retrieved from the SmartBuoy database. These may be manufacturers' sensor calibrations or the most current laboratory calibrations. Instruments are returned to the manufacturer and re-calibrated at regular intervals.
mV are converted to volts, where necessary.
LiCor signals are converted from Volts to PAR irradiance in µE m ^-2 s ^-1.
Salinity is derived from C and T using UNESCO 88 (PSS78) formula.
Burst data maximum and minimum ranges are checked and flagged if they fail the checks.
Burst means, result count, and result standard deviation are calculated from non-flagged burst data.
If there are data from two PAR sensors at different depths, Kd (m ^-1) is calculated for burst mean data only as LN(PAR1m/PAR2m).
Burst mean data maximum, minimum and rate of change checks are carried out and flags applied to any failures.
Time stamped burst and burst mean data with default units are stored on SmartBuoy database.

The data are now at QA status = 1.

Manual checks - Level 2

Level 1 burst mean data are now ready for manual QA procedures in order to progress to Level 2. Deployment notes are consulted for any comments on sensor performance or malfunction and post-deployment photographs of sensors, if available, are examined.

Cefas use a data visualisation tool to examine the SmartBuoy data.

A comparison is made between the end of one deployment with beginning of the next to identify possible drift and/or biofouling of OBS, Fluorometer, Salinity, PAR, and oxygen sensors.
Battery voltages are checked for sudden jumps and, if present, other sensors are examined for similar jumps to determine whether there is a problem with the sensor or if the buoy was disturbed.
Reference voltages on the FSI CT module are checked.
The standard deviation of OBS is examined. A steady increase in standard deviation is a good indication of the onset of biofouling. It is also used as a rough indicator for fluorometers during summer, except during spring, when there are large fluctuations in chlorophyll.
Li-Cor is examined for fouling, which could be indicated by a steady drop in daily maximum or a steady increase in standard deviation. If above-water Li-Cor data are available, they are used for comparison.
Pressure is examined for sudden decreases, indicating when the buoy was taken out of the water.
Roll and pitch are examined for any anomalies. It is expected that the spring/neap cycle will be present in the buoy tilt signal.
Where possible, comparison is made between burst mean data from sensors measuring the same variable. This is in order to determine whether there is a systematic offset (drift) or sensor fault and whether biofouling is present.
Comparison is made between burst mean sensor outputs from different variables as this can be helpful in determining the onset of biofouling. Any data that fail the checks are flagged with flags specific to the check that was failed.

Calibrations - Level 3

The combined information from Level 2 is used to determine the periods during which the data series are considered suspect. The data have now reached QA status = 2 and can progress to Level 3, where they will be fully calibrated with field-derived sample data.

For salinity an offset is calculated as the difference between result output from logger and the result from a discrete sample collected at the same time.
Calibration from regression analysis of field samples and logger output is applied to derive new parameters, e.g. chlorophyll calculated from fluorescence, suspended load calculated from OBS.
Chlorophyll calibrations are determined from GF/F filtered water samples, which are extracted in acetone and measured for fluorescence using a Turner Designs Fluorometer.
Suspended matter calibrations are determined from a known volume of water sample filtered through pre-weighed 0.4 µm Cyclopore filters. The filters are dried and reweighed to determine the weight of material per unit volume.
Salinity is calibrated using water samples that have been analysed with a Guildline Autosal salinometer.
Water samples from the Aqua Monitor are analysed for nutrients by colorimetric analysis of 0.4 µm Cyclopore-filtered samples.

The data have now reached QA status = 3 as time stamped, field calibrated burst mean data with parameter codes and units stored on SmartBuoy database with associated uncertainty or 95% confidence limits as appropriate. All SmartBuoy data banked at BODC have passed full Cefas QA procedures. Data that fail the Cefas QA checks are not submitted for banking.

SmartBuoy data processing by BODC

The following outlines the procedures that take place at BODC for banking Cefas SmartBuoy data.

BODC receives SmartBuoy data from Cefas after all quality checks have been passed and all possible calibrations applied. The data files are submitted as separate MS Excel spreadsheets for each parameter, i.e. there are separate files for temperature and salinity from the same instrument. An exact copy of the data is archived for safekeeping upon arrival.

Once the submitted data files are safely archived, the data undergo standard reformatting and banking procedures:

The data files are reformatted using an in-house program into a common format, which is a NetCDF subset.
Data files arising from the same instrument are combined into a single file.
Standard parameter codes are assigned that accurately describe the data.
Unit conversions are applied, if necessary, so that units are standardised. Oxygen concentration supplied by the originator in units of mg l ^-1 is converted to µmol l ^-1 by multiplying by 31.25.
The data are screened visually and any spikes or instrument malfunctions can be clearly labelled with quality control flags.
Comprehensive documentation is prepared describing the collection, processing and quality of each data series.
Detailed metadata and documents are loaded to the database and linked to each series so that the information is readily available to future users.

Project Information

Proudman Oceanographic Laboratory Coastal Observatory

The Coastal Observatory was established by Proudman Oceanographic Laboratory as a coastal zone real time observing and monitoring system. The main objective is to understand a coastal sea's response both to natural forcing and to the consequences of human activity. Near real-time measurements will be integrated with coupled models into a pre-operational coastal prediction system whose results will be displayed on the World Wide Web.

The Observatory is expected to grow and evolve as resources and technology allow, all the while building up long time series. A site selection pilot study was carried out in September 2001 and the Observatory became operational in August 2002.

The site is located in Liverpool Bay and is subject to typical coastal sea processes, with strong tides, occasional large storm surges and waves, freshwater input, stable and unstable stratification, high suspended sediment concentration and biogeochemical interaction. Measurements and monitoring will focus on the impacts of storms, variations in river discharge (especially the Mersey), seasonality and blooms in Liverpool Bay.

A variety of methods will be used to obtain measurements, including:

Moored instruments for in situ time series of currents, temperature and salinity profiles, and surface waves and meteorology. It is hoped that turbidity and chlorophyll measurements will be made at another site as the Observatory progresses;
The Cefas Smartbuoy for surface properties such as nutrients and chlorophyll, starting late 2002;
R.V. Prince Madog to carry out spatial surveys and service moorings;
Instrumented ferries for near surface temperature, salinity, turbidity, chlorophyll and nutrients. The first route will be Liverpool to Douglas, Isle of Man, starting late 2002;
Drifters for surface currents and properties such as temperature and salinity, starting in 2004;
Tide gauges, with sensors for meteorology, waves, temperature and salinity, where appropriate;
Meteorological data from Bidston Observatory and Hilbre Island, HF radar and tide gauge sites;
Shore-based HF radar measuring waves and surface currents out to a range of 50 km, starting in 2003;
Satellite data, with infrared for sea surface temperature and visible for chlorophyll and suspended sediment.

The partners currently involved with the project are listed below:

Proudman Oceanographic Laboratory
British Oceanographic Data Centre
UK Meteorological Office
Centre for Environment, Fisheries and Aquaculture Science
Environment Agency
Liverpool University and Port Erin Marine Laboratory
Bangor University School of Ocean Sciences
National Oceanography Centre Southampton
Department of Agriculture and Rural Development in Northern Ireland

A summary of Coastal Observatory cruises to date on R.V. Prince Madog is given in the table below:

Year	No. of cruises	Work summary
2001	1	Site selection and pilot study. 95 CTD casts.
2002	4	POL moorings deployed and serviced Cefas Waverider and SmartBuoy deployed and serviced 103 CTD casts
2003	10	POL moorings serviced Cefas Waverider and SmartBuoy serviced 341 CTD/LISST casts
2004	9	POL moorings serviced Cefas Waverider and SmartBuoy serviced 347 CTD/LISST casts
2005	9	POL moorings serviced Cefas Waverider and SmartBuoy serviced 268 CTD/LISST casts
2006	11	POL moorings serviced Cefas Waverider and SmartBuoy serviced 508 CTD/LISST casts
2007	9	POL moorings serviced Cefas Waverider and SmartBuoy serviced 471 CTD/LISST casts
2008	9	POL moorings serviced Cefas Waverider and SmartBuoy serviced 260 CTD/LISST casts
2009	7	POL moorings serviced Cefas Waverider and SmartBuoy serviced 213 CTD/LISST casts
2010	8	POL moorings serviced Cefas Waverider and SmartBuoy serviced 268 CTD/LISST casts
2011	6	POL moorings serviced Cefas Waverider and SmartBuoy serviced 307 CTD/LISST casts to date, ongoing

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd)	2006-12-15
End Date (yyyy-mm-dd)	2007-02-14
Organization Undertaking Activity	Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory
Country of Organization	United Kingdom
Originator's Data Activity Identifier	LB1_38/985
Platform Category	moored surface buoy

Smartbuoy deployment LB_038/POLRIG985

Deployment and Recovery

This rig was deployed as part of the Liverpool Bay Coastal Observatory during R.V. Prince Madog cruise PD37_06. The weather was stormy throughout the cruise (force 7 - 9), however, the moorings work was successfully achieved. Recovery of the rig took place during R.V. Prince Madog cruise PD02_07.

Rig Position	53 31.993N, 3 21.643W
Water Depth	24.4m
Deployed	15 December 2006 09:39
Recovered	14 Febuary 2007 13:19
No. of days	61

Rig Description

This rig is a single line mooring, comprising a surface CEFAS SmartBuoy and POL instrumentation suspended beneath. The single point mooring was mainly composed of 0.5 inch long link chain and marked at the surface by a 1.8 m diameter toroid (the CEFAS SmartBuoy) and anchored by a half tonne clump of scrap chain. The CEFAS Smartbuoy contains a suite of instruments mounted just below the surface.

The table below details the CEFAS instrumentation

Instrument	Serial Number	Parameters	Meter depth (m)	Record Length (days)
Seapoint Fluorometer	2245	Fluorescence Chlorophyll	1	43
Falmouth Scientific OEM CT sensor	1821	Temperature Salinity	1	61
Seapoint Turbidity meter	1433	Turbidity Suspended Load	1	61
LI-COR-192 Underwater Quantum sensor	20	PAR Vertical Light attenuation coefficient	1	61
LI-COR-192 Underwater Quantum sensor	8	PAR	2	61
EnviroTech WMS-2 Aqua Monitor water sampler	2326	Silicate Total Oxidised Nitrogen	1	52
EnviroTech NAS in situ nutrient analyser	2273	Total Oxidised Nitrogen	1	61
Aanderaa Oxygen Optode	127	Oxygen Concentration Oxygen Saturation	1	61

The table below details the POL instrumentation

Instrument	Serial Number	Meter Level	Parameters Measured	Sampling Interval	Comments
Sea-Bird MicroCAT SBE37-SM 485 V2.2	2991	5 m below surface	Temperature Conductivity	10 minutes	Upon recovery the clock was found to be running 30 s fast.
Sea-Bird MicroCAT SBE37-IM V2.1	4998	10 m below surface	Temperature Conductivity	10 minutes	-

Other Series linked to this Data Activity - 747499 747057 747451 747395 752951 747266 747162 747506 753026

Cruise

Cruise Name	PD37/06
Departure Date	2006-12-14
Arrival Date	2006-12-15
Principal Scientist(s)	Phil J Knight (Proudman Oceanographic Laboratory)
Ship	RV Prince Madog

Complete Cruise Metadata Report is available here

Fixed Station Information

Station Name	COA
Category	Offshore area
Latitude	53° 31.51' N
Longitude	3° 23.00' W
Water depth below MSL	26.0 m

Liverpool Bay Coastal Observatory Mooring Site A (COA/Site 1/Site 9)

This station is the main mooring site for the Proudman Oceanographic Laboratory (POL) Liverpool Bay Coastal Observatory and was first occupied in 2002. It is also known both as Coastal Observatory Site 1 and Site 9. POL perform two main types of activities at this station: they deploy moorings; and in addition, they take CTD profiles during each site visit. The station lies within a box of mean water depth 22.5 m with the following coordinates:

Box Corner	Latitude (+ve North)	Longitude (+ve East)
North-west corner	53.54097	-3.42958
South-east corner	53.50945	-3.33714

The position of this station relative to the other POL Coastal Observatory sites can be seen from the figure below.

BODC image

Mooring Deployment History

2011

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CTD, OBS, OXY	1117, 1121, 1125, 1127, 1130, 1132,	January - November
SmartBuoy	CTD x 2, AC-S, CT x 2, FL x 3, OBS x 2, PAR x 2, WMS, NAS, OXY, T x 2	1116, 1120, 1124	January - November

2010

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CTD, ADV, OBS	1086, 1090, 1094, 1098, 1102, 1106, 1109	January - December
SmartBuoy	CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T	1085, 1089, 1093, 1097, 1101, 1105, 1108, 1112	January - December

2009

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CTD, ADV, OBS	1055, 1062, 1067, 1071, 1074, 1078, 1082	January - December
SmartBuoy	CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T	1054, 1061, 1066, 1070, 1073, 1077, 1081	January - December

2008

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CTD, ADV, OBS	1024, 1028, 1032, 1036, 1041, 1044, 1047, 1051	January - December
SmartBuoy	CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T	LB1_047/1023, LB1_048/1027, LB1_049/1031, LB1_050/1035, 1040, 1043, LB1_053/1050	January - December

2007

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CTD, ADV, OBS	990, 997, 1001, 1005, 1010, 1014, 1017, 1021	January - December
SmartBuoy	CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD, T	LB1_039/989, LB1_040/996, LB1_041/1000, LB1_042/1004, LB1_043/1009, LB1_044/1013, LB1_045/1016, LB1_046/1020	January - December

2006

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CTD, ADV, OBS	951, 962, 966, 970, 974, 978, 982, 986	January - December
SmartBuoy	CT x 2, FL x 2, OBS, PAR x 2, WMS, NAS, CTD, OXY, BD	958, 961, 965, 969, 973, 977, LB1_037/981, LB1_038/985	January - December

2005

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	ADCP, CT	913, 914, 921, 925, 929, 933, 938, 942, 945, 949	January - December
SmartBuoy	CT, FL, OBS, PAR, WMS, NAS, OXY	912, 920, 924, 928, 932, 937, LB1_028/941, LB1_029/944, LB1_030/948	January - December
Frame with telemetry buoy	ADCP	914	March - April

2004

Rig Type	Typical Instruments	Rig IDs	Comment
Frame	BPR, ADCP, TR, CT	890, 892, 893, 896, 898, 900, 902, 904, 907, 908, 910, 911	January - December
SmartBuoy	CT, FL, OBS, PAR, WMS, NAS	889, 891, 895, 897, 899, 901, 903, 906, 909	January - December
Frame with telemetry buoy	ADCP	893, 908, 911	April - May, October - December

2003

Rig Type	Instruments	Rig IDs	Comment
Frame	BPR, ADCP, TR, CT	861, 864, 866, 869, 872, 878, 880, 883, 885, 887, 888	January - December
SmartBuoy	CT, FL, OBS, PAR, WMS, NAS	863, 865, 867, 870, 871, 877, 879, 882, 884, 886	January - December

2002

Rig Type	Instruments	Rig IDs	Comment
Frame	BPR, ADCP, TR, CT	851, 854, 856, 858	August - December
Line mooring	CT x 3	853, 855	August - November
SmartBuoy	CT, FL, OBS, PAR, WMS, NAS	857, 860	November - December

2001

Rig Type	Instruments	Rig IDs	Comment
Frame	ADCP, OBS	838, 839, 840, 841, 843, 844, 845, 846, 848, 849	September

CTD Sampling History

Year	Number of Cruises	Total Casts per year
2011	6	116 including a 46 cast tidal cycle from 2011-04-18 to 2011-04-19 and a 51 cast tidal cycle station from 2011-07-27 to 2011-07-28
2010	8	71 including a 52 cast tidal cycle station from 2010-04-28 to 2010-04-29
2009	7	21
2008	9	75 including a 54 cast tidal cycle station from 2008-05-13 to 2008-05-14
2007	8	71 including a 51 cast tidal cycle station from 2007-05-15 to 2007-05-16
2006	9	72 including a 53 cast tidal cycle station from 2006-05-09 to 2006-05-10
2005	9	41 including a 22 cast tidal cycle station from 2005-04-05 to 2005-04-06
2004	9	77 including a 54 cast tidal cycle station from 2004-05-11 to 2004-05-12
2003	10	28
2002	4	13

The CTD instrument package for these cruises was a Sea-Bird 911plus, with beam transmissometer, fluorometer, LICOR PAR sensor, LISST-25, and oxygen sensor.

Key

AC-S = Absorption and attenuation spectrophotometer
ADCP = Acoustic Doppler Current Profiler
ADV = Acoustic Doppler Velocimeter
BD = Bacterial degradation experiment
BPR = Bottom Pressure Recorder
CT = Conductivity and temperature logger
CTD = Conductivity, temperature, depth sensor
FL = Fluorometer
NAS = in-situ nutrient analyser
OBS = Optical Backscatter Turbidity meter
OXY = Oxygen sensor
PAR = PAR sensor
T = Temperature logger
TR = Transmissometer
WMS = Automatic water sampler

Other Series linked to this Fixed Station for this cruise - 747057 747162 747266 747395 747451 747499 747506 752951 753026 753118 1003634 1003646 1623408

Other Cruises linked to this Fixed Station (with the number of series) - CO 01/12 (5) PD01/08 (17) PD01/11 (14) PD02/03 (10) PD02/05 (11) PD02/07 (15) PD02/09B (17) PD02/10 (15) PD04/06 (1) PD05/10 (16) PD06/04 (12) PD06/07 (16) PD07/08 (14) PD07/11 (17) PD09/06 (11) PD09/07 (64) PD09/08 (16) PD10/03 (9) PD10/10 (14) PD11/04B (13) PD11/05 (9) PD11/11 (57) PD12/05 (2) PD12/09 (16) PD13/07 (14) PD14/08 (67) PD16/06 (9) PD16/07 (15) PD17/03 (12) PD17/10 (15) PD18/04 (13) PD18/05 (11) PD18/09 (17) PD19/08 (2) PD20/02 (7) PD20/06 (9) PD20/07 (17) PD21/05 (10) PD21/10 (15) PD21/11 (9) PD22/04 (13) PD22/06 (9) PD23/03A (10) PD23/07 (15) PD23/08 (13) PD24/02 (2) PD24/09 (17) PD25/03B (12) PD25/05 (11) PD25/06 (9) PD25/11 (7) PD27/07 (17) PD29/04 (12) PD29/06 (9) PD29/08 (14) PD29/10 (17) PD30/05 (10) PD31/02 (11) PD31/03 (12) PD32/04 (12) PD33/08 (5) PD33/09 (16) PD34/03 (12) PD34/05 (10) PD35/02 (11) PD35/06 (14) PD36/10 (16) PD37/08 (18) PD38/03 (13) PD38/04 (12) PD38/09 (16) PD41/05 (11) PD43/11 (11) PD44/03 (7) PD47/09 (15) PD48/03 (5) PD48/04 (8) PD48/05 (10) PD49/10 (14) PD52/04 (8)

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