Metadata Report for BODC Series Reference Number 1221852

• 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

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

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

Detection

Electrical

Physical

* 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:

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:

• give early warning of any fundamental change in Atlantic ecosystem functionng
• improve forecasts of the future ocean state and associated socio-economic impacts
• provide a "contextual" logistical and scientific infrastructure for independently-funded national and international open ocean biogeochemical and ecological research.

The specific objectives are:

• To collect hydrographic, chemical, ecological and optical data on transects between the UK and the Falkland Islands
• To quantify the nature and causes of ecological and biogeochemical variability in planktonic ecosystems
• To assess the effects of variability in planktonic ecosystems on biogenic export and on air-sea exchange of radiatively active gases

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

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: