Metadata Report for BODC Series Reference Number 1221759


Metadata Summary

Data Description

Data Category Meteorology -unspecified
Instrument Type
NameCategories
TriOS RAMSES ACC-UV Hyperspectral UVA and UVB Radiometer  radiometers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Tim Smyth
Originating Organization Plymouth Marine Laboratory
Processing Status banked
Project(s) Oceans 2025 Theme 10 SO1:AMT
 

Data Identifiers

Originator's Identifier UV_LATLON_111015
BODC Series Reference 1221759
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2011-10-15 07:18
End Time (yyyy-mm-dd hh:mm) 2011-10-15 20:38
Nominal Cycle Interval 300.0 seconds
 

Spatial Co-ordinates

Start Latitude 16.42650 N ( 16° 25.6' N )
End Latitude 14.97390 N ( 14° 58.4' N )
Start Longitude 35.70480 W ( 35° 42.3' W )
End Longitude 34.70260 W ( 34° 42.2' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth -15.0 m
Maximum Sensor Depth -15.0 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed 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)
ACYCAA01 1 Dimensionless Record_No Sequence number
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
VSRAUVAW 1 Watts per square metre DWIrr_UVA Downwelling vector irradiance as energy (ultra-violet A wavelengths) in the atmosphere by cosine-collector radiometer
VSRAUVBW 1 Watts per square metre DWIrr_UVB Downwelling vector irradiance as energy (ultra-violet B wavelengths) in the atmosphere by cosine-collector radiometer
 

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

AMT21 RRS Discovery (D371) Surface UV Measurements Data Quality Report

Data Quality Report

This appears to be a good quality data series. The data have a strong diurnal signal with spikes occurring during the daylight hours. No BODC flagging took place.


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

AMT21 RRS Discovery (D371) Surface UV Measurements Instrumentation

Instrument Serial number Parameter
TriOS RAMSES-ACC-UV SAM_81a2 UVA and UVB

TriOS RAMSES-ACC-UV radiometer

Basic Information

This is a spectral radiometer measuring over the UV band range (280-500 nm) with a cosine-response to measure irradiance. It is fitted with a 256 channel silicon photodiode array with channels giving 2.2 nm/pixel and a spectral accuracy of 02 nm. Typical saturation (4ms integration time) is 20 W m-2 nm-1 sr-1 (at 300 nm), 17 W m-2 nm-1 sr -1 (at 360nm), 18W m-2 nm-1 sr -1 (at 500nm). Typical NEI (8ms integration time) is 0.85 µW m-2 nm-1 sr -1 (at 300nm), 0.75 µW m-2 nm-1 sr -1 (at 360nm), 0.80 µW m-2 nm-1 sr -1 (at 500nm). Acuuracy is quoted as being better than 6-10 per cent depending on spectral range.

Performance Specifications

Optics

wavelength range* 280 - 500 nm
detector type* 256 channel silicon photodiode array
spectral sampling*: 2.2 nm/pixel
spectral accuracy: 0.2 nm
usable channels: 100
typical saturation (4ms integration time): 20 W m -2 nm -1 sr -1 (at 300nm)
17 W m -2 nm -1 sr -1 (at 360nm)
18 W m -2 nm -1 sr -1 (at 500nm)
typical NEI (8ms integration time): 0.85 µW m -2 nm -1 sr -1 (at 300nm)
0.75 µW m -2 nm -1 sr -1 (at 360nm)
0.80 µW m -2 nm -1 sr -1 (at 500nm)

Detection

collector type: cosine response
accuracy: better than 6-10% (depending on spectral range)

Electrical

integration time: 4 ms - 8 sec (user selectable or auto [4 ms - 4096 ms])
telemetry data interface: RS232 or Serial Bus
data rate (RS232): 1,200 - 19,200 baud
power requirements: 1.5 - 11 VDC
0.85mW (data acquisition active)
100mW (interface active)
0.5mW (stand-by modus)
connector: SubConn micro 5 pin male

Physical

size: dia. 4.83 cm x 26 cm (without connector)
weight in air: <1.0 kg (stainless steel / POM housing)
depth range: 300m
operating temperature: -10°C to +50°C

* specifications from Carl ZEISS, Germany

Further information may be found in the TriOS RAMSES brochure .

AMT21 RRS Discovery (D371) Surface UV Measurements Processing Document

Originator's Processing

A Trios Rameses ACC UV sensor was set up high on the ship's starboard winch control cabin and configured to log hyperspectral UV between 200 and 500 nm at 2.5nm resolutuion every 5 minutes through daylight hours. The data can either be kept at hyperspectral or integrated over broadband (UV-A and UV-B) ranges.

The data were fully calibarated by a calibration carried out by TRIOS in May 2011. The data were split into the UVA and UVB components using the idl rouitine trios_uv_deck.pro. The data were subsequently placed into daily files.

Investigations have found that the calibration of the instruments drifts dramatically during cruises. The data have not been corrected for this drift.

Data were submitted to BODC as text files with each individual file name dusing the convention yymmdd_uva_uvb.txt as each file represented a a day of UV measurement on the cruise.

BODC Processing

The data were received and archived BODC system. Due to missing longitude and latitude in the originator's files latitude and longitude were merged to the file from the underway navigation data file. The data were then processed and loaded to the databse.

Parameters

Parameter codes defined in the BODC parameter dictionary were assigned to the variables as shown in the table below:

Originator's Parameter Originator's Units BODC Parameter Code BODC Parameter Units BODC Description
UVA W/(m^2) VSRAUVAW Watts per square metre Downwelling vector irradiance as energy (ultra-violet A wavelengths) in the atmosphere by cosine-collector radiometer
UVB W/(m^2) VSRAUVBW Watts per square metre Downwelling vector irradiance as energy (ultra-violet B wavelengths) in the atmosphere by cosine-collector radiometer
N/A N/A ALATGP01 Degrees Latitude north (WGS84) by unspecified GPS system
N/A N/A ALONGP01 Degrees Longitude east (WGS84) by unspecified GPS system

Screening

Data has a strong diurnal signal with some spikes. UVA and UVB have very similar signals which is encouraging for the accuracy and consistency of the data. Considered to be a good data series and no BODC flagging has taken place.


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 D371 (AMT21)
Departure Date 2011-09-29
Arrival Date 2011-11-13
Principal Scientist(s)Glen A Tarran (Plymouth Marine Laboratory)
Ship RRS Discovery

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