Metadata Report for BODC Series Reference Number 1918956

• 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

BAS Long Term and Monitoring Survey James Clark Ross Cruise JR20101221 (JR245, JR246, JR247) Underway Meteorology Quality Control Document

The primary sensors (CDTAZZ01 and CRELZZ01) did not log any data throughout the cruise. The final file includes only the data from the secondary sensors. Several periods of null data were identified:

• 18/12/2010 18:39:00 hours to 19/12/2010 13:02:00 hours
• 30/12/2010 14:07:00 hours to 30/12/2010 14:59:00 hours
• 01/01/2011 11:57:00 hours to 01/01/2011 11:59:00 hours
• 01/01/2011 14:51:00 hours to 01/01/2011 15:18:00 hours
• 02/01/2011 14:16:00 hours to 02/01/2011 14:29:00 hours

Addind to these gaps in the data, several periods of fairly constant data were identified in CRELZZ02. These periods were not flagged as they were not considered anomalous.

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

Gill Windobserver 70 (ultrasonic) anemometer

A solid state, heated ultrasonic anemometer. Designed for use within the aviation industry and for more extreme weather conditions. It measures the times taken for an ultrasonic pulse of sound to travel from the North transducer to the South transducer, and compares it with the time for a pulse to travel from S to N transducer. Likewise times are compared between West and East, and E and W transducer. The wind speed and direction (and the speed of sound) can then be calculated from the differences in the times of flight on each axis. This calculation is independent of factors such as temperature. It uses 150 Watts of electrical heating in the anemometer head to prevent icing. Wind speed accuracy is +/-2% at 12 m/s. Wind direction accuracy is +/-2 degrees at 12 m/s.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/Gill_WindObserver70_2017.pdf

Kipp and Zonen PAR Lite Photosynthetically Active Radiation sensor

An atmospheric radiometer that measures photosynthetically active radiation (PAR) by means of a Teflon diffuser, an optical interference filter and a photo-diode detector. The sensor measures the PAR 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 optical filter has a spectral response of 400-700 nm (PAR wavelengths) and the photodiode creates a voltage output that is proportional to the incoming radiation.

Specifications

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

BAS Long Term and Monitoring Survey James Clark Ross Cruise JR20101221 (JR245, JR246, JR247) Underway Meteorology Instrumentation Document

The instruments used to collect the data set are presented in the table below. All instruments, except the anemometer, which was on a mast 22.5 m above sea level, were located on the ship's meteorological mast, the sensors were placed side by side, 20 m above sea level.

BAS Long Term and Monitoring Survey James Clark Ross Cruise JR20101221 (JR245, JR246, JR247) Underway Meteorology Processing Procedures Document

Originator's Data Processing

Cruises JR245, 246 and 247 were amalgamated into one cruise. JR245 was 19 days of the Western Core Box cruise, JR246 was 2 days of Hotspots and JR247 was 7 science days for an AFI project (The role of krill grazing in Southern Ocean nutrient cycles). In addition there was an AFI-CGS (Individual physiological and behavioural responses of krill to distributional shifts and thermal change) project undertaken. All three projects were focussed on investigating Antarctic krill (Euphausia superba) and it was therefore sensible to combine them into one cruise focused around South Georgia.

Wind speed and direction and PAR were processed by the originator in Unix and Matlab using modified versions of programs developed by Mike Meredith (BAS) and then read over into netCDF format. Procedures included data loading and visual checks for the positioning streams. The remaining meteorology parameters were processed at the BAS Polar Data Centre (BAS-PDC) as it was either not processed by the originator or the data sent by the originator could not be converted to a format compatible with BODC's specifications.

The procedures applied by the originator include:

• check for duplicate dates and times
• standardising time
• check for gaps in data
• check data against defined thresholds
• flagging
• unit conversion

File delivered to BODC

BODC Data Processing

The files mentioned above were selected for data banking as they contain the best version of processed meteorological parameters. All meteorological were matched to BODC codes and transferred to internal BODC format using established procedures. Unit conversions were applied to relative wind speed as the data supplied by the originator was in knots and the units in the BODC dictionary are m s^-1.

BODC processing procedures included loading of data and reduction through averaging, visual screening and flagging of anomalous values. The originator's variables were mapped to appropriate BODC parameter codes as follows:

anemom_jr245_01

jr245_ocl _exactsec

ocl_jr245_cal

Screening

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.

Absolute 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

Only one PAR channel was processed by the originator. Both TIR channels exhibit a similar quality. M flags were applied to the night periods on all channels.

Air Pressure

Both channels were screened and they exhibit a similar quality. Several periods with no data were identified:

• 18/12/2010 18:39:00 hours to 19/12/2010 13:02:00 hours
• 30/12/2010 14:07:00 hours to 30/12/2010 14:59:00 hours
• 01/01/2011 11:57:00 hours to 01/01/2011 11:59:00 hours
• 01/01/2011 14:51:00 hours to 01/01/2011 15:18:00 hours
• 02/01/2011 14:16:00 hours to 02/01/2011 14:29:00 hours

Air Temperature and Relative Humidity

All channels were screened and it was clear that the primary sensors experienced difficulties during the cruise. The final file contains data for CRELZZ02 and CDTAZZ02 only.

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

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: