Metadata Report for BODC Series Reference Number 1759831

• 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

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

iSTAR RRS James Clark Ross Cruise JR20140126 (JR294, JR295) Underway Document

Cruise details

The cruise is part of the Ice Sheet Stability prgramme (iSTAR) which aims to investigate the ocean processes that are thought to enhance melting of the Pine Island Glacier in the Amundsen Sea. The cruise includes two NERC-funded ISTAR projects. ISTAR A, or Ocean2ice, supports a consortium led by UEA and addresses processes at the continental shelf break and on the continental shelf that affect the heat delivered to the ice shelf front, together with the subsequent fate of the ice shelf meltwater. The second is ISTAR B, led by BAS, which addresses the processes that affect the warm water once it has entered the ice shelf cavity.

The ship departed Punta Arenas, Chile, on 26 January 2014 and docked in Rothera on 8 March 2014 where the scientific crew desimbarked. The data submitted to BODC covers a period from 20 January 2014 to 04 March 2014, which includes the whole cruise period, plus transit from Punta Arenas and to Rothera. The extra days of data will not be included in the final file.

Delays in the planned work were mainly due to weather conditions rangin from stormy seas to fog and ice floes which prevented the ship from progressing at normal speed.

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.

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

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

Ashtech GG24 receiver

The GG24 is an all-in-view Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) receiver that blends GPS and GLONASS into a single position solution. This receiver uses all available satellites from both systems to obtain the best position information.

The three-dimensional position and velocity are calculated when tracking any combination of five satellites. Up to five independent measurements are determined every second, with no interpolation or extrapolation from previous solutions.

Specifications

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

Ashtech Global Positioning System receivers (ADU series)

The ADU series of Global Positioning System (GPS) receivers are designed to give real-time three-dimensional position and attitude measurements. Attitude determination is based on differential carrier phase measurements between four antennas connected to a receiver, providing heading, pitch and roll, along with three-dimensional position and velocity.

The ADU2 model receives information from 48 channels, while the upgraded model (ADU5) uses 56 channels. The ADU5 also features a unique Kalman filter with user selectable dynamic modes to match operating conditions. It also incorporates signals from Satellite Based Augmentation Systems (SBAS) and features an embedded 2-channel 300 kHz beacon receiver for easy differential GPS (DGPS) operations.

Specifications

Further details can be found in the manufacturer's specification sheets for the ADU2 andADU5.

Kongsberg Seatex Seapath 200 GPS and Gyrocompass

The Seapath 200 is a highly accurate, real-time heading, attitude and position information system that integrates the best signal characteristics of Inertial Measurement Units (IMU) and Global Positioning System (GPS), using a differential GPS method to acquire this data.

The high-rate motion data is obtained from the Seatex MRU5 inertial sensor and two fixed baseline GPS carrier-phase receivers. The raw data is integrated in a Kalman filter in the Seapath Processing Unit. The IMU contains an accurate linear accelerometer and Bosch Coriolis force angular rate gyros (CFG).

This system is equipped to utilise up to six different DGPS reference stations, it checks for consistency within measurements from the different sensors to ensure reliability and rejects noisy data or reports its inaccuracy. The data is available through various output protocols, RS-232, RS-422 and Ethernet.

This instrument is no longer in production; the main characteristics are presented below, and the specification sheet can be accessed here Kongsberg Seatex Seapath 200 .

Specifications

Litre Meter flow meter

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

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.

iSTAR RRS James Clark Ross Cruise JR20140126 (JR294, JR295) Underway Surface Hydrography Document

Content of data series

Instrumentation

The sea surface hydrographical suite of sensors was fed by the pumped-seawater, non-toxic supply. The seawater intake was located approximately 6.5 m below the sea surface. The SBE 38 sea surface temperature sensor was located towards the hull near the seawater intake. All other sensors were located in the clean seawater laboratory on the main deck, directly above the intake pipe.

Data Processing Procedures

Originator's Data Processing

Surface hydrography, navigation and meteorological data were recorded throughout the cruise using an automated Matlab script. All data collection and processing was performed automatically by a procedure that triggers processing and then copies the resulting matlab dataset and figures to a shared drive. The main matlab script queries the SCS data streams provided by the JCR and imports the data into matlab, concatenating with data from previous previous days. The matlab script then proceeds to calculate additional variables before plotting each variable both as crude track maps and timeseries for rapid data visualisation and organising the data in a structure format.

The originator's file contains 5 substructures, flag (which contains a flag indicating potential issues with the raw data), clean (contains the raw data with all values flagged replaced by NaN), info (contains general file metadata), scripts (text conpies of the scripts for redeploying in future cruises) and raw (raw data with no quality control information.

One file, in matlab format, was submitted to BODC and contains all the variables for the three data types, Navigation, Meteorology and Surface Hydrography. Sampling frequency of the submitted data was of 60 seconds.

File delivered to BODC

BODC Data Processing

The file mentioned above were selected for data banking as they contain the best version of surface hydrography data. Data were banked at BODC following standard data banking procedures, including reduction through averaging and screening the data for anomalous values.

The originator's variables were mapped to appropriate BODC parameter codes as follows:

Oceanlogger.mat

Sea surface temperature

The originator noted that TMESSG01 was higher than expected,both channels were screened and exhibit a similar quality, with TMESSG01 recording slightly higher temperatures (~ 1°C) than TEMPHU01. M flags applied to TMESSG01 where anomalous values were identified (in general before periods of absent data).

Salinity and Conductivity

M flags applied both channels where anomalous values were identified (in general before periods of absent data).

Chlorophyll

No flags applied.

Calibration

No information on calibrations against independent measurements were provided to BODC.

Quality control report

Several periods of absent data were identified during screenign. These data were removed by the originator prior to submission to BODC. M flags applied to TMESSG01, PSALSU01 and CNDCSG01 for the following periods:

• 28/01/2014 16:30:00 hours to 28/01/2014 16:32:00 hours
• 02/02/2014 16:14:00 hours to 02/02/2014 16:18:00 hours
• 03/02/2014 11:11:00 hours to 03/02/2014 11:15:00 hours
• 03/02/2014 16:43:00 hours to 03/02/2014 16:46:00 hours
• 04/02/2014 11:30:00 hours
• 04/02/2014 11:36:00 hours to 04/02/2014 11:38:00 hours
• 05/02/2014 11:52:00 hours to 05/02/2014 11:56:00 hours
• 06/02/2014 11:07:00 hours to 06/02/2014 11:12:00 hours
• 21/02/2014 12:27:00 hours to 21/02/2014 12:28:00 hours
• 25/02/2014 10:45:00 hours to 25/02/2014 10:50:00 hours
• 26/02/2014 17:48:00 hours to 26/02/2014 17:51:00 hours
• 26/02/2014 18:29:00 hours
• 27/02/2014 10:34:00 hours to 27/02/2014 10:36:00 hours
• 27/02/2014 15:25:00 hours
• 27/02/2014 17:06:00 hours to 27/02/2014 17:07:00 hours
• 28/02/2014 04:03:00 hours to 28/02/2014 04:04:00 hours
• 01/03/2014 16:24:00 hours to 01/03/2014 16:27:00 hours
• 01/03/2014 18:52:00 hours to 01/03/2014 18:54:00 hours
• 03/03/2014 01:34:00 hours to 03/03/2014 01:36:00 hours
• 03/03/2014 03:18:00 hours

Problem report

NA

Project Information

The Ice Sheet Stability (iSTAR) programme

Background and objectives

The iSTAR programme aims to measure the rate that ice is being lost from the West Antarctic ice sheet, and to improve our understanding of what might be driving this loss how it is changing over time. The rate of loss of water from ice in glaciers in the Antarctic (and Greenland) is more than the amount of water being deposited in these areas by precipitation. This has changed our understanding of these systems and the rate of ice loss is a matter of interest for sea level and climate research. Improving our understanding of the processes and impacts of changes to these systems is vital for better predictions for sea level rise in the future and will feed in to climate research. This programme combines scientific research of glaciers and the surrounding ocean environment (including how they impact each other). Research about the oceans was focused on the Amundsen Sea Sector of West Antarctica with instruments deployed from the research ship RRS James Clark Ross. Research about the ice was focused on Pine Island Glacier, Thwaites Glacier and Union Glacier with measurements taken during two expeditions across the ice. This programme was funded by the Natural Environment Research Council (NERC)

The programme is split in to four projects:

Ocean2ice: Processes and variability of ocean heat transport toward ice shelves in the Amundsen Sea Embayment (iSTAR A)

Ocean under ice: Ocean circulation and melting beneath the ice shelves of the south-eastern Amundsen Sea (iSTAR B)

Dynamic ice: Dynamical control on the response of Pine Island Glacier (iSTAR C)

Ice loss: The contribution to sea-level rise of the Amundsen Sea sector of Antarctica (iSTAR D)

Participants

The iSTAR research programme is managed by British Antarctic Survey (BAS) on behalf of NERC. Operational support, in the form of logistics planning and infrastructure, and Communication and Knowledge Exchange support are provided by BAS. There are four science projects and participants in these projects represent the following organisations:

• British Antarctic Survey
• National Oceanography Centre
• Newcastle University
• Scott Polar Research Institute
• University College London
• University of Bristol
• University of East Anglia
• University of Edinburgh
• University of Leeds
• University of Southampton
• University of St. Andrews
• University of Tasmania
• University of Washington

Fieldwork and data collection

A wide range of data parameters were collected for this programme. Physical and chemical measurements of the ocean close to and next to the ice shelf were made using instruments deployed from ship, on moorings, on autonomous platforms and seal tags. Measurements were also made of the glaciers and ice shelfs including radar and seismic surveys and ice cores. There were also meteorological and atmospheric measurements taken. For more information about the data collected on each of the four projects see the project web pages.

Data management

Data management for ocean data will be done by the British Oceanographic Data Centre whilst ice data will be managed by the Polar Data Centre.

For more information about iSTAR programme see the: iSTAR Programme Website

Ocean2ice: Processes and variability of ocean heat transport toward ice shelves in the Amundsen Sea Embayment (iSTAR A)

Background and objectives

Ocean2ice (otherwise referred to as iSTAR A) is a project that is part of NERC's Ice Sheet Stability programme. The project was designed to investigate how relatively warm water gets close to and beneath glaciers in the Antarctic and what impact this warm water has on the rate of ice melt at these sites. This research and collection of data will to feed in to climate and sea level forecasting and research. This project was funded by the Natural Environment Research Council.

Participants

The principal investigator for the Ocean2ice project is Professor Karen Heywood, University of East Anglia. Other participants in the project represent the following organisations:

• British Antarctic Survey
• National Oceanography Centre
• University of East Anglia
• University of Southampton
• University of St. Andrews

Fieldwork and data collection

Oceanographic data were collected from a wide range of instruments from the research ship RRS James Clark Ross between 26 January and 08 March 2014 in the Amundsen Sea. Data collected include measurements of the physical conditions (including temperature and salinity), current speeds and directions, chemical measurements of the water column (including oxygen and chlorophyll-a concentrations). A fleet of Seagliders (ocean robots that measure physical parameters including temperature, salinity and current speeds and directions) were also deployed to measure conditions close to the ice shelf. Moorings were deployed by the project and have measured conditions in the area over a couple of years. In addition Seal tags (small sensors glued to the fur of seals which fall off when the seals moult their fur) were deployed and transmit data back via satellite networks to scientists. These seal tag deployments give the scientists the rare opportunity to measure water properties below the ice shelf.

Data management

All data collected by the Ocean2ice project are to be submitted to the British Oceanographic Data Centre for careful storage, quality control, archiving and distribution to scientists, education, industry and the public.

For more information about Ocean2ice see the iSTAR A project page

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: