Metadata Report for BODC Series Reference Number 1759818

• 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.

Kipp & Zonen Photosynthetically Active Radiation Quantum Sensor PQS1

The PQS1 is an atmospheric radiometer designed to measure incident radiation at photosynthetically active radiation (PAR) wavelengths. It incorporates a diffuser with an excellent directional (cosine) response and a silicon photodiode detector.

If used in field research applications, the PQS1 can be connected with the METEON handheld display unit, which also as data-logging capability. For permanent installations, it can be connected to the LOGBOX SD data logger.

Specifications

A link to the PQS1 specification sheet can be found here: PQS1 Spec sheet

Kipp and Zonen SP Lite and SP Lite2 Silicon Pyranometer

An atmospheric pyranometer that measures solar radiation over the range 400-1100 nm by means of a silicon photo-diode detector mounted in a diffuser. The sensor measures the radiation received over the entire hemisphere and the diffuser's sensitivity is proportional to the cosine of the angle of incidence of the incoming radiation. The photodiode creates a voltage output that is proportional to the incoming radiation. The SP Lite2 supersedes the SP Lite and features an improved sensitivity and faster response time than its predecessor.

Specifications

Further details can be found in the manufacturer's specification sheets for the SP Lite and SP Lite2.

Rotronic Hygromet MP102H and MP402H temperature and humidity probes

This meteorological probe measures humidity and temperature with the plug-in HygroClip HC2-S3 sensor module, and can also be equipped with a signal conditioned Pt100 temperature probe.

The two models differ in that the MP102H produces a voltage output while the MP402H produces a current output. Other characteristics are common to both models.

The specification sheet can be accessed here Rotronic MP102H and MP402H.

Specifications

Vaisala PTB210 Digital Barometer

The basic specifications for this pressure sensor are as follows:

• Manufacturer: Vaisala
• Type: Silicon capacitive sensor
• Model: PTB210
• Range: 900 - 1100 hPa
• Output: 0-5VDC
• Total Accuracy (20°C): ±0.30hPa
• Operating temperature: -40 to +60 deg C
• Weight: 110g
• Certification Ingress Protection: IP65

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

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

Content of data series

Instrumentation

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.

Positioning instruments were located on the ship's monkey island, above the bridge, the anemometer was located on a mast, approximately 20 m above the surface and the remaining meteorological sensors on the meteorological platform located on the ship's bow.

File delivered to BODC

BODC Data Processing

The file mentioned above were selected for data banking as they contain the best version of meteorology data. Data were banked at BODC following standard data banking procedures, including reduction through averaging, correcting the wind for anemometer orientation (0° to the bow) and screening the data for anomalous values.

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

Oceanlogger.mat

The file also contain true wind u,v, speed and direction which was not transferred as according to BODC's standard procedures, it is re-derived in house. Additionally the file contaied navigation and surface hydrography parameters, which will be dealt with in the appropriate documentation.

Data from the secondary atmospheric temperature and relative humidity sensors areavailable upon request. Secondary TIR and atmospheric pressure data were found to be null.

All data expressed at measurement altitude. All the reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag, missing data by both setting the data to an appropriate value and setting the quality control flag.

Calibration

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

Wind speed and direction

Relative wind speed and direction were corrected for the ship's heading and speed using the gyrocompass heading, ship velocities (calculated at BODC from the main positional channels) and an anemometer orientation of 0° on the bow.

PAR and TIR

Night periods were values were slightly negative were flagged M. There is a known issue with the sensors absorbing heat during the day and releasing it during the night periods, which might cause negative readings. Another possible cause for these values is an offset in the cailbration coefficients.

During screening it was found that the second PAR sensor didn't record valid data. This channel was dropped from the final file.

Air pressure

Both channels were screened and it was found that the second atmospheric pressure sensor data were almost completely null, therefore it was not included in the final file.

Air Temperature and Relative Humidity

All channels were screened and duplicate sensors for both paramaters exhibit similar quality. Several periods with no data were identified. These have been removed by the originator prior to submission.

Quality control report

M flags applied to absolute wind speed and direction prior to conversion to relative wind parameters. Both channels exhibited periods with values of 0.0, as they were considered anomalous, an M flag was applied to the identified cycles. M flags aplied to PAR and TIR sensors when slightly negative values were identified during the night period.

Problem report

Not applicable

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: