Metadata Report for BODC Series Reference Number 1762200


Metadata Summary

Data Description

Data Category Meteorology -unspecified
Instrument Type
NameCategories
Vaisala HMP temperature and humidity sensor  meteorological packages
Gill Windsonic anemometer  anemometers
Vaisala PTB 210 digital barometer  meteorological packages
Kipp and Zonen CM6B pyranometer  radiometers
Skye Instruments SKE510 PAR energy sensor  radiometers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Mr John Seddon
Originating Organization National Marine Facilities Sea Systems
Processing Status banked
Project(s) Oceans 2025 Theme 10 SO1:AMT
 

Data Identifiers

Originator's Identifier JC053_PRODQXF_MET
BODC Series Reference 1762200
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2010-10-12 10:40
End Time (yyyy-mm-dd hh:mm) 2010-11-22 21:10
Nominal Cycle Interval 60.0 seconds
 

Spatial Co-ordinates

Southernmost Latitude 48.10750 S ( 48° 6.4' S )
Northernmost Latitude 50.75433 N ( 50° 45.3' N )
Westernmost Longitude 56.12467 W ( 56° 7.5' W )
Easternmost Longitude 1.36100 W ( 1° 21.7' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth -19.4 m
Maximum Sensor Depth -17.1 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Scattered at fixed depths - The sensors are scattered with respect to depth but each remains effectively at the same depth for the duration of the series
Sensor Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum -
 

Parameters

BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
CAPHTU01 1 Millibars Air_press Pressure (measured variable) exerted by the atmosphere by barometer and expressed at measurement altitude
CDTASS01 1 Degrees Celsius AirTemp Temperature of the atmosphere by dry bulb thermometer
CRELSS01 1 Percent Air_RelHumid Relative humidity of the atmosphere by humidity sensor
CSLRRP01 1 Watts per square metre Port_solar Downwelling vector irradiance as energy (solar (300-3000nm) wavelengths) in the atmosphere by port-mounted pyranometer
CSLRRS01 1 Watts per square metre Stbd_solar Downwelling vector irradiance as energy (solar (300-3000nm) wavelengths) in the atmosphere by starboard-mounted pyranometer
DWIRRPSD 1 Watts per square metre Port_SurfVPAR Downwelling vector irradiance as energy (PAR wavelengths) in the atmosphere by port-mounted cosine-collector radiometer
DWIRRSSD 1 Watts per square metre Stbd_SurfVPAR Downwelling vector irradiance as energy (PAR wavelengths) in the atmosphere by starboard-mounted cosine-collector radiometer
EWDASS01 1 Degrees True WindDirFrom Wind from direction in the atmosphere by in-situ anemometer
EWSBSS01 1 Metres per second WindSpd Wind speed in the atmosphere by in-situ anemometer
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

AMT RRS James Cook Cruise JC053 AMT20 Meteorology Data Quality Document

The meteorology data have been through BODC quality control screening. Some intermittent flagging of data have been made. Overall the data for the cruise duration appear good. Additional notes are provided from the NMF technicians' report where anomalies in the data were apparent due to problems with the sensors during the cruise.

Atmospheric pressure

At 19:32 on 25th October there was a spike in the atmospheric pressure value and then an 8 millibar drop. There were further drops in the sensor's output during the day and at 21:27 on the same day the NMF technician noted the pressure sensor was reading 1001.2 millibar while the bridge's BATOS pressure sensor read 1009.2 millibar. Heavy rain prevented the met platform junction box from being opened for several days. When the rain stopped it was found that a connecter above the pressure sensor had worked loose and rain water had dripped past the connector's gasket and onto the pressure sensor. The connector was tightened. The other pressure sensor was not on-board as it was being calibrated. Gradually the pressure sensor's reading approached a similar value to BATOS's but with high frequency noise of magnitude 0.3 to 0.4 millibar superimposed on it. There were also occasional steps away from the true value, e.g. between 13:55 and 15:10 on November 19th.

Air temperature and humidity

From 04:00 until 12:00 on 2nd November the temperature and humidity probe's data was incorrect. Heavy rain appeared to have got into the screen protecting the probe. After the rain had stopped, the probe quickly dried out and the data returned to normal. The met platform was visited to check all of instruments between 13:20 and 13:35 on the same day resulting in spikes in the data. A repeat event happened between 03:42 and 06:20 on 21st November.

Wind channels

During the cruise the NMF technicians noted that for several days the processed true wind speed from the Surfmet and Level-C systems showed a decrease from the rest of the days' true wind speed when the ship was stopped on station. The met platform was visited and it was found that although the anemometer was situated above everything else on the met platform, when the wind came over the port bow, the search light and ocean colour monitoring experiment caused turbulence to the air flow that reduced the velocity of the wind passing through the anemometer. While the ship was steaming the wind came from a different angle and so the correct wind velocity was measured. At 10:55 on 29th October the anemometer was raised by 0.65 m in the hope that it would then be above the turbulence from other items on the met platform. No further drops in wind velocity were observed as the ship turned.

The relative wind speed and direction channels show natural variation and fluctuation but there were no values or trends that stood out as unrealistic. There were 'steps' in the channel but this is related to the vessel coming on to or leaving station. No additional flags were added. The absolute wind speed and direction channels were screened and a few spikes flagged suspect.

Irradiance channels

During the cruise the port and starboard PAR sensors were plotted with their calibration factors applied and there was a consistent difference between the two sensor values. On the 8th November the PAR sensors were swapped around with the spare sensor (sn 28560) for comparison. After applying each sensor's calibration factor it was found that sensor 28562 was under reading in comparison to the other 2 sensors by ~5%. At 11:05 on 10th November sensor 28560 replaced 28562 in the starboard PAR sensor position.

The data in the TIR and PAR channels did not require further flagging as it is unclear whether the variation is due to changing cloud cover etc.


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

AMT RRS James Cook Cruise JC053 AMT20 Meteorology Instrument Description Document

Sensor Serial number Last calibration date Deployment
Gill Wind sonic (Option 3) 064537 - Port
Skye Instruments SKE510 28562 2009-04-29 Starboard until 2010-11-10
Skye Instruments SKE510 28560 2009-04-29 Starboard from 2010-11-10
Skye Instruments SKE510 28561 2009-04-29 Port
Kipp and Zonen Ltd CMB6 973135 2009-04-20 Starboard
Kipp and Zonen Ltd CMB6 973134 2009-04-20 Port
Vaisala PTB210 R0450005 2010-09-15 Port
Vaisala HMP45A C1320001 2010-04-06 Port

Gill Instruments Windsonic Anemometer

The Gill Windsonic is a 2-axis ultrasonic wind sensor that monitors wind speed and direction using four transducers. The time taken for an ultrasonic pulse to travel from the North to the South transducers is measured and compared with the time for a pulse to travel from South to North. Travel times between the East and West transducers are similarly compared. The wind speed and direction are calculated from the differences in the times of flight along each axis. This calculation is independent of environmental factors such as temperature.

Specifications

Ultrasonic output rate 0.25, 0.5, 1, 2 or 4 Hz
Operating Temperature -35 to 70°C
Operating Humidity < 5 to 100% RH
Anemometer start up time < 5 s
Wind speed
Range 0 to 60 m s -1
Accuracy ± 2% at 2 m s -1
Resolution 0.01 m s -1
Response time 0.25 s
Threshold 0.01 m s -1
Wind direction
Range 0 to 359°
Accuracy ± 3° at 12 m s -1
Resolution
Response time 0.25 s

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

Kipp and Zonen Pyranometer Model CM6B

The CM6B pyranometer is intended for routine global solar radiation measurement research on a level surface. The CM6B features a sixty-four thermocouple junction (series connected) sensing element. The sensing element is coated with a highly stable carbon based non-organic coating, which delivers excellent spectral absorption and long term stability characteristics. The sensing element is housed under two concentric fitting Schott K5 glass domes.

Specifications

Dimensions (W x H) 150.0 mm x 91.5 mm
Weight 850 grams
Operating Temperature -40°C to +80°C
Spectral Range 305 - 2800 nm
(50% points)
Sensitivity 9 -15 µV/W/m 2
Impedance (nominal) 70 - 100 ohm
Response Time (95%) 30 sec
Non-linearity < ± 1.2% (<1000 W/m 2 )
Temperature dependence of sensitivity < ± 2% (-10 to +40°C)
Zero-offset due to temperature changes < ± 4 W/m 2 at 5 K/h temperature change

Skye Instruments PAR Energy Sensor Model SKE 510

The SKE 510 is suitable for measuring photosynthetically active radiation (PAR) from natural or artificial light sources. The sensor is fully waterproof and guaranteed submersible to 4m depth, and indoor versions are also available.

The instrument uses a blue-enhanced planar diffused silicon detector to measure energy (in W m -2 ) over the 400-700 nm waveband. It has a cosine-corrected head and a square spectral response. The sensor can operate over a temperature range of -35 to 70 °C and a humidity range of 0-100% RH.

Specifications

Sensitivity (current) 1.5µA or 100 W m -2
Sensitivity (voltage) 1mV or 100 W m -2
Working Range 0-5000 W m -2
Linearity error 0.2%
Absolute calibration error typ. less than 3%
5% max
Response time - voltage output 10 ns
Cosine error 3%
Azimuth error less than 1%
Temperature co-efficient ±0.1% per °C
Internal resistance - voltage output c. 300 ohms
Longterm stability ±2%
Material Dupont 'Delrin'
Dimensions 34 mm diameter
38mm height
Cable 2 core screened
7 - 2 - 2C
Sensor Passband 400 - 700 nm
Detector Silicon photocell
Filters Glass type and/or metal interference

Vaisala PTB210 Digital Barometer

The basic specifications for this pressure sensor are as follows:

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

Vaisala Temperature and Relative Humidity HMP Sensors

A family of sensors and instruments (sensors plus integral displays or loggers) for the measurement of air temperature and relative humidity. All are based on a probe containing a patent (HUMICAP) capacitive thin polymer film capacitanece humidity sensor and a Pt100 platinum resistance thermometer. The probes are available with a wide range of packaging, cabling and interface options all of which have designations of the form HMPnn or HMPnnn such as HMP45 and HMP230. Vaisala sensors are incorporated into weather stations and marketed by Campbell Scientific.

All versions operate at up to 100% humidity. Operating temperature ranges vary between models, allowing users to select the version best suited to their requirements.

Further details can be found in the manufacturer's specification sheets for the HMP 45 series , HMP 70 series and HMP 230 series .

AMT RRS James Cook Cruise JC053 AMT20 Meteorology Processing Procedures Document

Originator's Data Processing

The meteorology component consisted of a suite of sensors mounted on the foremast at a height of approx 16.4m above the waterline. Parameters measured were wind speed and direction, air temperature, humidity and atmospheric pressure. There was also a pair of optical sensors mounted on gimbals on each side of the ship. These measured total irradiance (TIR) and photo-synthetically active radiation (PAR).

The data from the meteorological sensors were logged by the TECHSAS system during the cruise and combined in the RVS Level-C format to produce the file 'surfmet'. The following instruments were logged during the cruise:
1) Gill Wind sonic (Option 3)
2) Skye Instruments SKE510 (port and starboard)
3) Kipp and Zonen Ltd CMB6 (port and starboard)
4) Vaisala PTB100A
5) Vaisala HMP45A

No processing was carried out using the RVS software suite on meteorology channels.

Filename Data type Start Calendar Day Start Time Finish Calendar Day Finish Time Interval
surfmet RVS Level-C raw 2010-10-12 07:50:36 2010-11-22 21:10:09 1 second

BODC Data Processing

The 'surfmet' files were used as the source data for transfer. A description of the channels present in the files, units, whether they were transferred, BODC parameter code and units, and if a unit conversion was applied during the transfer are detailed in the table below:

surfmet Channels Description Units BODC Parameter Code Units Conversion Factor
press Atmospheric pressure at measurement height - no sea level correction 1 hPa CAPHTU01 1 mbar *1
ppar Raw port PAR sensor voltage 10 -2 mV DVLTRPSD V *10 -5
spar Raw starboard PAR sensor voltage 10 -2 mV DVLTRSSD V *10 -5
speed Relative wind speed m s -1 ERWSSS01 m s -1 *1
direct Relative wind direction Degrees ERWDSS01 Degrees *1
airtemp Air temperature Degrees Celsius CDTASS01 Degrees Celsius *1
humid Air humidity Percent CRELSS01 Percent *1
ptir Raw port TIR sensor voltage 10 -2 mV CVLTRP01 V *10 -5
stir Raw starboard TIR sensor voltage 10 -2 mV CVLTRS01 V *10 -5

Wind channels - calculation of absolute values

The BODC Matlab procedure 'wincor' was run using relative wind speed and direction, the ship's north-south and east-west velocities with the vane set to 0 degrees at the bow to generate absolute wind speed (EWSASS01) and direction (EWDASS01).

Irradiance channels (PAR and TIR) - conversion from voltages using manufacturer's calibrations

The voltages were converted to W m -2 using the coefficients on the calibration sheets provided.

Calibrations

No calibrations were applied by BODC to these data.

Screening

Each data channel was inspected on a graphics workstation using BODC screening software EDSERPLO and any spikes or periods of dubious data were flagged using BODC quality control flag system. Impossible values were checked carefully and flagged null only if believed to be genuine missing or bad data. EDSERPLO was used to carry out comparative screening checks between channels by overlaying data channels. A map of the cruise track was simultaneously displayed in order to take account of the oceanographic context.


Project Information

Oceans 2025 Theme 10, Sustained Observation Activity 1: The Atlantic Meridional Transect (AMT)

The Atlantic Meridional Transect has been operational since 1995 and through the Oceans 2025 programme secures funding for a further five cruises during the period 2007-2012. The AMT programme began in 1995 utilising the passage of the RRS James Clark Ross between the UK and the Falkland Islands southwards in September and northwards in April each year. Prior to Oceans 2025 the AMT programme has completed 18 cruises following this transect in the Atlantic Ocean. This sustained observing system aims to provide basin-scale understanding of the distribution of planktonic communities, their nutrient turnover and biogenic export in the context of hydrographic and biogeochemical provinces of the North and South Atlantic Oceans.

The Atlantic Meridional Transect Programme is an open ocean in situ observing system that will:

The specific objectives are:

The measurements taken and experiments carried out on the AMT cruises will be closely linked to Themes 2 and 5. The planned cruise track also allows for the AMT data to be used in providing spatial context to the Sustained Observation Activities at the Porcupine Abyssal Plain Ocean Observatory (SO2) and the Western Channel Observatory (SO10).

More detailed information on this Work Package is available at pages 6 - 9 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/


Data Activity or Cruise Information

Cruise

Cruise Name JC053 (AMT20)
Departure Date 2010-10-12
Arrival Date 2010-11-25
Principal Scientist(s)Andrew Rees (Plymouth Marine Laboratory)
Ship RRS James Cook

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:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

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

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain