Metadata Report for BODC Series Reference Number 1205434

• 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

Problem Reports

No Problem Report Found in the Database

Alloa Quality Report

Screening and QC

The data have had QC applied by SEPA with suspect data being removed. Data then went through BODC QC procedures.

During screening noisy periods were observed in several parameters, but these were left unflagged. M flags were applied to spikes and to slightly negative values in TURBXXXX, ODSDM021 and CPHLZZXX. In the TURBXXXX and CPHLZZXX channels there were also negative vlaues which where less than -1 NTU and -1 mg m^-3 respectively that were flagged null. These values are available on request. Null values were assigned an N flag.

Prolonged periods with constant data were also considered anomalous and flagged, these can be identified for TEMPPR01 in a number of series including 1205004 and 1205028. Several series also exhibit anomalous TEMPPR01 data which were flagged (e.g. series 1204916, 1204941, 1204953, 1204965, 1204989, 1205028, 1205053, 1205065).

A period with anomalous DOXYSZZ01, PHXXZXX and PSALZZXX has been identified in series 1205201 (from 18 August 2009 12:00 hours to 21 August 2009 11:00 hours). After some investigation, it was decided not to assign any quality flags as it these data were found to be related with a meteorological event. Although readings are considered to be valid, the data should be used with caution.

For some series, TURBXXXX and CPHLZZXX exhibit some high values which might be related with particles adhering to the sensor. These instances have not been flagged.

Ship service visits were taken at a single point in time, where stated in the originator's data.

Data Access Policy

Open Data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

YSI 6-Series multiparameter water quality sondes

Basic information

Comprehensive multi-parameter, water quality monitoring sondes. Designed for long-term monitoring, profiling and spot sampling. The 6-series may be split into several categories: V2 Sondes, 600 Sondes, Drinking Water Sondes and System. Each category has a slightly different design purpose with V2 Sondes ideal for long-term monitoring with a greater number of parameters, whereas 600 sondes are ideal for specific applications with fewer parameters available.

Model features/parameters

^*Freshwater only^**Calculated parameters

Sensor Specifications

For further information, please see the manufacturer's manual and data sheet.

SEPA Mooring Instrumentation

The SEPA long-term monitoring project has obtained hydrographic data across various moorings through the deployment of a YSI 6600 multi-parameter-sonde attached to a fixed mooring buoy at the surface of the water column.

These mooring sites include: Dunoon, Gunnet Ledge, Inner Clyde Estuary, Campbelltown, Loch Striven, Ythan, Loch Sunart, South Alloa, and Moray Firth.

The South Alloa site had two Hydrolab MS5 probes up until the 3rd of March 2011, at which point a YSI 6600 probe was used.

The Inner Clyde Estuary site also has a probe attached approximately 1 m from the sea floor in addition to the probe at the surface.

The Moray Firth site was monitored solely between July and December 2018.

The depth of the sensors at the time of measurement at each site is available upon request for the 2016 and 2017 data.

The turbidity sensors are deemed, by the manufacturer, to be used as guidance in events such as observing storm events or spotting discharges. SEPA rely on a suspended solids laboratory procedure for their turbidity reported data. The same situation occurs for chlorophyll, SEPA have a lab method they use to report it as high turbidity can interfere with the readings. This is not generally an issue in low turbidity areas.

BODC processing of SEPA's long-term monitoring buoys

Data Acquisition and Transfer

The data were sent by SEPA as yearly .csv files and following BODC's procedures the files were checked for consistency and subsequently archived.

The data were reformatted to QXF format using BODC's established procedures. During the transfer process each yearly file was split into cruise-to-cruise series events. The table below shows how the originator's parameters were mapped to BODC parameters and their units:

Data Quality and Screening

Not all parameters occur in all series, particularly pH, turbidity and chlorophyll.

Oxygen saturation is not derived by BODC for consistency across all years and due to missing channels as mentioned in the originator's processing document.

The standard unit conversion factor of * 31.252 was applied to oxygen concentration during transfer to obtain the BODC units of µmol/l. (Bittig et al., 2018)

Post transfer analysis and crosschecks were applied according to BODC procedures. This involved the screening of data to check flags were appropriately applied whilst also applying further quality control flags where appropriate. Originator flags for "No sensor; Quality Control failure; Quality Control Spike Removed; Quality Control Spike removed, wiper incorrectly parking over sensor; Power Failure, Sensor failure" were all flagged as 'Null' as no data were available when these were applied.

References

Bittig, H., Körtzinger, A., Johnson, K., Claustre, H., Emerson, S., Fennel, K., ... & Xing, X. 2018. SCOR WG 142: Quality Control Procedures for Oxygen and Other Biogeochemical Sensors on Floats and Gliders. Recommendations on the conversion between oxygen quantities for Bio-Argo floats and other autonomous sensor platforms.

SEPA originator's processing document for Alloa long-term monitoring buoy

Data Acquisition and Analysis

Data were obtained from a probe attached to a mooring deployed in Firth of Forth, off Alloa. The mooring was serviced and deployed by the Scottish Environment Protection Agency (SEPA) for the purpose of long-term monitoring. Up to 3 March 2011, a Hydrolabs probe was used and subsequently replaced by a YSI 6600 probe.

The raw data were downloaded directly from the instruments, occasional problems during the remote downloading of data meant that sometimes strings were overwritten, leading to one parameter being downloaded at the expense of another. So although all parameters were measured, not all were included in the originator's files. Data were downloaded in local time and following discussion with BODC they were then corrected to GMT before being submitted.

Quality and Screening

Once downloaded the data went through SEPA data quality checks with suspect data removed and relevant flags attached to inform future users of the reason for any missing data. This information is available upon request.

Submission

The data were then submitted to BODC through ftp as yearly .csv files.

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

SEPA South Alloa Fixed Station Mooring

The buoy is located in the upper Forth estuary, near Alloa, and provides measurements of dissolved oxygen, salinity, temperature, pH, chlorophyll and turbidity. Its maintenance is done on a monthly basis using one of SEPA's support vessels and is done in such a way as to prevent loss of information, for more recent records, this includes a change in the probe that is installed in the buoy, thus making readings continuous through time.

Up until July 2010, the sampling interval was set to collect a measurement every 15 minutes. From then until July 2014, a measurement was collected every 30 minutes. From this point, a sample was collected every 15 minutes. This buoy has also seen a change in the measurement probes, up to 3 March 2011, the measurements were collected with a Hydrolab Ms5, which was subsequently replaced by a YSI 6600 probe.

More information may be found at the SEPA monitoring buoy network page for Alloa.

Related Fixed Station activities are detailed in Appendix 1

BODC Quality Control Flags

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

SeaDataNet Quality Control Flags

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

Appendix 1: SEPA_Alloa

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.