Metadata Report for BODC Series Reference Number 1814862

• 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

The transmissometer signal consistently decreased from a cleaning event throughout the cruise. It was thought this was due to trapped bubbles in the sensor optical cell. The data should be used with caution. (BODC assessment).

RRS James Cook cruise JC142 surface hydrography quality control report

General comments

The non-toxic water supply was active from 09:59:25 on 30^th October 2016 until 00:08:00 on 24^th November 2016 and from 03:20:00 on 26^th November 2016 until 06:55:00 on 7^th December 2016 (Ship technician assessment). All sea surface hydrography channels were flagged until sensors had stabilised when the seawater supply was turned on. The data were flagged from when the sensors exhibited unusual readings close to when the non-toxic supply was turned off. (BODC assessment).

The non-toxic water supply was turned off and the sensors cleaned at intervals throughout the cruise details below. Transmissometer readings were taken after cleaning with the sensor in open air and closed off to light, readings are also below. (Ship technician assessment). The data were flagged appropriately (BODC assessment).

Chlorophyll and fluorescence

The fluorometer appeared faulty from the start of the cruise until a cleaning event on the 15/11/2016 at approx. 13:20 after which, the sensor gave sensible readings. The data were flagged suspect prior to this point. (BODC assessment).

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

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:

All models:

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

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

RRS James Cook cruise JC142 surface hydrography instrumentation

Instrumentation

The sea surface hydrographical suite of sensors was fed by the pumped-seawater, non-toxic supply. The depth of the seawater intake was at 5.5 m.

The following surface hydrology sensors were fitted:

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

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

RRS James Cook cruise JC142 surface hydrography data processing procedures

Originator's Data Processing

The data were logged by the TECHSAS (TECHnical and Scientific sensors Acquisition System) version 5.11 data logging system into daily NetCDF files which were provided to BODC for processing. Data was additionally logged into the RVS Level-C format which have been archived at BODC.

Files delivered to BODC

BODC Data Processing

The files were reformatted to BODC internal format using standard data banking procedures. All files were averaged to 60 second intervals. The following table shows how the variables within the files were mapped to appropriate BODC parameter codes:

*-*-Surf-JC-SM_JC1.SURFMETv2

*-*-SBE45-SBE45_JC1.TSG

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

Calibration

Field Calibrations

No calibration against independent variables were applied to these data.

Manufacturers Calibrations

Transmissometer

The transmissometer voltage channel was converted to beam transmission ( beamtrans ) and beam attenuation ( atten ) as follows:

beamtrans [%] = ([ volts - Vdark ] / [ Vref - Vdark ])100

atten [per m] = (-1/ pathlength ) ln( beamtrans /100)

where Vdark = 0.058 V, Vref = 4.649 V and pathlength = 0.25 m.

Fluorometer

The fluorescence voltage channel was converted to engineering units ( chla ) using the following calibration:

chla [µg/L]= SF ( volts - CWO )

where SF = 5.6 µg/L/V and CWO = 0.064 V.

Project Information

MarineE-tech Research Programme

MarineE-tech is a four year (2016-2020) research programme, jointly funded by the Natural Environment Research Council (NERC), Security of Supply of Mineral Resources (SoS Minerals), Engineering and Physical Sciences Research Programme (EPSRC), and the Sao Paulo Research Foundation (FAPESP). The aim of the programme is to improve understanding of E-tech element concentration in seafloor mineral deposits, in particular Cobalt Crusts (ferromanganese-cobalt-rich deposits), which are considered the largest yet least explored source of E-tech elements globally. Research will focus on two key aspects: The formation of the deposits, and reducing the impacts resulting from their recovery.

Background

Minerals are essential for economic development, the functioning of society and maintaining our quality of life. Consumption of most raw materials has increased steadily since World War II, and demand is expected to continue to grow in response to the burgeoning global population and economic growth, especially in Brazil, Russia, India and China (BRIC) and other emerging economies. We are also using a greater variety of metals than ever before.

New technologies such as those required for modern communication and computing and to produce clean renewable, low-carbon energy require considerable quantities of many metals. In light of these trends there is increasing global concern over the long-term availability of secure and adequate supplies of the minerals and metals needed by society. Of particular concern are 'critical' raw materials (E-tech elements), so called because of their growing economic importance and essential contribution to emerging 'green' technologies, yet which have a high risk of supply shortage.

The primary focus of the programme is on the processes controlling the concentration of these E-tech deposits and their composition at a local scale (10s to 100s square km). This will involve data gathering by robotic vehicles across underwater mountains and small, deep-sea basins off the coast of North Africa and Brazil. By identifying the processes that result in the highest grade deposits, we aim to develop a predictive model for their occurrence worldwide. Also to be addressed is how to minimise the environmental impacts of mineral recovery.

Further details are available on the MarineE-tech website.

Participants

Nine different organisations are directly involved in research for MarineE-tech. These institutions are:

• National Oceanography Centre (NOC) - Project Chief Scientist: Dr Bramley Murton
• British Geological Survey (BGS)
• University of Bath
• University of Leicester
• HR Wallingford
• Marine Ecological Surveys Limited (MESL)
• University of Sao Paulo
• Secretariat of the Pacific Community (SPC)
• Soil Machine Dynamics Limited (SMD)

Research details

Overall, two Science Goals and five Work Packages have been funded and are described in brief below:

Science Goal 1: Assess the processes controlling the genesis of marine Fe-Mn deposits and their E-tech element composition

The objective of Work Packages 1, 2 and 3 are to characterise local-scale environmental variables and their influence on the formation and composition of Fe-Mn deposits and hence to ultimately develop predictive models for these deposits. This work addresses Science Goal 1 of the NERC Programme (E-tech element cycling) and forms the central component of our proposal. It is made possible by the opportunity to deploy robotic underwater vehicles and instruments that will enable the detailed studies required to make significant advances in the understanding of these systems and their E-tech element budgets.

• Work Package 1: Local-scale processes, seafloor morphology, sampling and primary data interpretation (UK lead: NOC).

• Work Package 2: Physical and chemical characterisation of crusts, development of a litho-,bio- and chemo-stratigraphic framework (BGS lead).

• Work Package 3: Work package 3: Assessment of the role of microbes in E-tech element concentration and cycling and implications for bioprocessing (NOC lead with USP).

Science Goal 2: Environmental Impacts

• Work Package 4: Assessing the environmental impacts of Fe-Mn oxide deposit exploitation and E-Tech element extraction on periphery ecosystems (Marine Ecological Surveys Ltd, SOPAC and HR Wallingford).

• Work Package 5: Low-carbon extraction of E-Tech elements from Fe-Mn deposits (University of Bath lead).

Fieldwork and data collection

The project has two dedicated cruises: A UK expedition (JC142) sailed during late 2016 to the Tropic Seamount, north-east Atlantic, on the RRS James Cook. A further cruise is scheduled for 2017 and 2018 by the University of Sao Paulo focusing on the Rio Grande Rise and Sao Paulo Ridge, south-west Atlantic Ocean.

Activities will involve the deployment of underwater robotic technology including the ISIS Remotely Operated Vehicle (ROV) to sample over 100 locations of Fe-Mn crusts. Also to be utilised is the Autosub6000 Autonomous Underwater Vehicle (AUV) to image the lateral extent and thickness of crusts across the seamounts. Plume studies will also be undertaken to assess their impacts on peripheral ecosystems.

Data Activity or Cruise Information

Cruise

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:

SeaDataNet Quality Control Flags

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