Metadata Report for BODC Series Reference Number 1676777

• 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

Non-toxic (underway) sea water supply

A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.

Pigments for Charles Darwin and RRS Challenger cruises

Document History

Converted from CDROM documentation.

Content of data series

Data Originator

Dr Ken Jones, CCMS Dunstaffnage Marine Laboratory, UK.

Sampling strategy and methodology

Charles Darwin cruises CD91B, CD93A and CD93B and RRS Challenger cruises CH121A, CH121B, CH121C, CH123A, CH123B, CH125A, CH125B, CH126A, CH126B, CH128A and CH128B.

Samples were collected from either the non-toxic surface sea water supply or from Niskin bottles fitted to the CTD rosette. They were taken in Nalgene bottles, rinsed twice with sample water prior to filling.

The samples were vacuum filtered through 2.5 cm GF/F filters. The volume of water filtered varied depending on the particulate load in the sample. The filters were folded and immediately frozen.

Back in the laboratory, the filters were extracted into 8 ml of 90% neutralised acetone and stored for between 18 and 36 hours in a refrigerator. The extracts were centrifuged at 3000 rpm for two 5-minute bursts.

The resulting chlorophyll solutions were assayed on a bench fluorometer. Three drops of 8% HCl were added and the assay was repeated. Chlorophyll-a and phaeopigment concentrations were determined from the two fluorometer readings using the equations in Tett and Grantham (1978).

References

Tett P. and Grantham B. 1978. A simple guide to the measurement and interpretation of chlorophyll concentration, temperature and salinity, in coastal waters. SMBA. 85pp.

Project Information

LOIS Shelf Edge Study (LOIS - SES)

Introduction

SES was a component of the NERC Land Ocean Interaction Study (LOIS) Community Research Programme that made intensive measurements from the shelf break in the region known as the Hebridean Slope from March 1995 to September 1996.

Scientific Rationale

SES was devoted to the study of interactions between the shelf seas and the open ocean. The specific objectives of the project were:

• To identify the time and space scales of ocean-shelf momentum transmission and to quantify the contributions to ocean-shelf water exchange by physical processes.

• To estimate fluxes of water, heat and certain dissolved and suspended constituents across a section of the shelf edge with special emphasis on net carbon export from, and nutrient import to, the shelf.

• To incorporate process understanding into models and test these models by comparison with observations and provide a basis for estimation of fluxes integrated over time and the length of the shelf.

Fieldwork

The SES fieldwork was focussed on a box enclosing two sections across the shelf break at 56.4-56.5 °N and 56.6-56.7 °N. Moored instrument arrays were maintained throughout the experiment at stations with water depths ranging from 140 m to 1500 m, although there were heavy losses due to the intensive fishing activity in the area. The moorings included meteorological buoys, current meters, transmissometers, fluorometers, nutrient analysers (but these never returned any usable data), thermistor chains, colour sensors and sediment traps.

The moorings were serviced by research cruises at approximately three-monthly intervals. In addition to the mooring work this cruises undertook intensive CTD, water bottle and benthic surveys with cruise durations of up to 6 weeks (3 legs of approximately 2 weeks each).

Moored instrument activities associated with SES comprised current measurements in the North Channel in 1993 and the Tiree Passage from 1995-1996. These provided boundary conditions for SES modelling activities.

Additional data were provided through cruises undertaken by the Defence Evaluation and Research Agency (DERA) in a co-operative programme known as SESAME.

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: