BODC's Argo data in the ANDRO Atlas

The Argo data set — collected from a global network of 3000 profiling floats — provides the first opportunity to investigate sub-surface ocean circulation. Since 2000, data from more than 6000 Argo floats has been collected worldwide, generating around 800,000 profiles.

Argo floats descend to a depth of 1500 to 2000 metres, typically, and drift at this depth for nine days before rising to the surface. During the ascent a temperature and salinity profile is collected. These data are then transmitted via satellite before the float starts another cycle.

However, scientific efforts to understand the oceans' sub-surface circulation has been hindered by several data issues. For example

• invalid data when floats became grounded
• incomplete information — missing positional or depth information
• inconsistent international metadata standards

BODC contribution to ANDRO for the layer 750-1250 dbar in the Atlantic Ocean. ©

To address this, the ANDRO Atlas aims to produce a reliable global atlas of Argo ocean sub-surface trajectories. ANDRO is led by Michel Ollitrault (Ifremer, France) with much of the analysis conducted by Jean-Philippe Rannou from the French company Altran.

The Atlas covers 10 years of Argo data spanning 1999 to 2009 and, funding permitting, will include data from all Argo participant countries. Once complete it will be an unprecedented database of direct and absolute measurements of the ocean circulation down to a depth of 2000 metres.

The British Oceanographic Data Centre (BODC), the Data Assembly Centre (DAC) for Argo floats from the UK, Ireland, Mauritius and Saudi Arabia, submitted more than 30,000 raw data profiles from over 300 floats to ANDRO in late 2010. Analysis of these data is now complete and they have contributed to the Atlas in the North Atlantic, South Atlantic, Indian and Southern oceans.

Feedback from the data analysis, primarily relating to the inconsistent metadata standards, will be used by BODC over the coming year to improve the quality and scientific value of the BODC-hosted Argo float data. It is also anticipated that the feedback will form the basis for the development of new standard practices within the global Argo community.

BODC awarded prestigious medals

The British Oceanographic Data Centre (BODC) is proud to announce that the prestigious UNESCO Intergovernmental Oceanographic Commission (IOC) 50^th Anniversary Commemorative Medal has been awarded to

• Dr Lesley Rickards — Deputy Director of BODC and Director of the Permanent Service for Mean Sea Level (PSMSL)

• Dr Meirion Jones — former Director of BODC

• Dr Nicholas Flemming — former Head of the Marine Information and Advisory Service (MIAS) — from which BODC was born — and ex-Director of EuroGOOS, the European Global Ocean Observing System

The IOC 50^th Anniversary Commemorative Medal ©

The IOC, which held its first assembly in 1961, was set up "to promote international cooperation and to coordinate programmes in research, services and capacity building, in order to learn more about the nature and resources of the ocean and coastal areas and to apply that knowledge for the improvement, management, sustainable development and protection of the marine environment and the decision making process of its Member States."

Medals were awarded, as part of the IOC 50^th Anniversary celebrations, to those deemed to have made a substantial contribution to the work of IOC. In its citation, IOC says that recipients "...are decorated for their exemplary dedication to the IOC, for their devotion to the IOC mission and for their continuing support to IOC activities."

Altogether, 43 individuals selected by the Medal Nomination Committee, based on Member States and committee members recommendations, were presented with medals during the 50^th Anniversary Closing Ceremony on 22 June 2011. Prof. Philip Woodworth (National Oceanography Centre and former Director PSMSL) and Dr Harry Dooley (former International Council for the Exploration of the Sea (ICES) Oceanographer and leader of joint ICES-IODE data management activities) were other medal recipients from the UK.

More information and biographies of all medal recipients is available from the IOC web site.

The long way round

A British Oceanographic Data Centre (BODC) Data Scientist, Mike Nelson, took part in the RRS Discovery cruise D365 in the Northeast Atlantic Ocean. He joined a team of marine scientists from various centres to make measurements along the Extended Ellett Line.

The Extended Ellett Line, an oceanographic section that runs from Scotland to Iceland, crosses the main pathways of warm, salty water flowing towards the Arctic Ocean.

'Stormtrooper Mike' coping with the ash cloud! ©

It is important for investigating oceanic climate variability and is one of the few long-term monitoring datasets in the North Atlantic Ocean, with measurements being collected along the section at regular intervals since 1975. With over 80 cruises having worked the Ellett Line and the Extended Ellett Line, BODC provides access to a wealth of data from this section.

Coping with Mother Nature!

For most people, the word 'cruise' conjures up images of cocktails and sunbeds. However, the reality of a research cruise - particularly in rough seas - is very different. Imagine completing your daily tasks whilst riding a Big Dipper; even sleep becomes impossible for all but the hardiest of seamen!

On cruise 365, after sailing through the relatively sheltered waters of the Irish Sea, Discovery headed out to the west coast of Scotland to start the planned data collection. Almost immediately the forecast storm force winds (~ 65 mph) struck.

With conditions too dangerous to deploy the scientific equipment, she was forced to seek shelter among the islands of the Hebrides. To avoid the worst of the weather, a decision was made to sail north and restart the sampling programme working along the section from Iceland toward Scotland.

Unexpectedly, this route took Discovery straight into the ash cloud from the recently erupted Grimsvotn volcano! Filthy but unscathed, she eventually made it to Iceland's jagged islands and the fabled 'midnight twilight'. From then on it was plain sailing and, despite mother nature's best efforts, most of the planned scientific work was completed.

Why do BODC take part in research cruises?

While onboard a research cruise our Data Scientists gain first-hand experience of sampling techniques and data processing methodologies. This improves our efficiency when ingesting the data into the National Oceanographic Database (NODB). They also help coordinate metadata (information about data) collection, which saves us a lot of time when the data arrive at BODC.

Working alongside colleagues in testing and tiring conditions improves their understanding of how inaccuracies in metadata might occur and developing a good relationship with the scientists, the ship's technicians and students helps remedy these issues.

Ultimately this aids BODC towards its goal of providing a large and accessible marine data resource for the scientific community and the general public.

Today's recipe: Better science through better data management

Data are a key part of the scientific record. A compendium of recipes to make data management digestible has been produced by the Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) Data Management Committee.

Download the IMBER Data Management Cookbook - A Project Guide to good Data practices (414 KB).

The Cookbook's 'recipes' are in no way restricted to IMBER. They should be suitable for any marine research project that gathers data and wants them to be available and useful in the long term.

The IMBER Data Management Cookbook. A Project Guide to good Data practices. ©

Stages of data management

The Cookbook describes data management roles and stages including

• Project planning: early stages
• Project planning: late stages
• Cruise planning: before the cruise
• Cruise planning: during the cruise
• After the cruise: early stages
• After the cruise: late stages

What's cooking? Why not data management?!

Why do most researchers consider data management to be the poor relation to writing papers? Perhaps this is because journal publications are used as an indicator of professional productivity, and can be referenced in other publications using a unique code or Digital Object Identifier (DOI).

However, a good quality data set is a more objective legacy as it is not biased by interpretation. It can be reused and compared with other data sets. Yet the creation of a good quality and well documented data set does not currently bring the same official recognition to its author(s).

However, as the Cookbook suggests, this is about to change. A number of working groups are looking into developing well documented procedures so that the same principles of publication and citation can be applied to well managed data.

The Cookbook will help Principal Investigators and collaborators understand what is needed for good data management.

Reference

The IMBER Data Management Cookbook - A Project Guide to good Data practices (2011).
Pollard R.T., Moncoiffé G. and O'Brien T.D.
IMBER Report No. 3, IPO Secretariat, Plouzané, France. 16pp.

BODC maintains Investors in People (IIP) standard

The British Oceanographic Data Centre (BODC) first achieved the Investors in People (IIP) standard in March 2002 and we are delighted to announce that we have just passed a post-recognition review.

IIP is a national quality standard that defines a level of good practice for improving an organisation's performance through its people.

BODC is an "Investor in People" ©

Our staff are our most important asset and we are dedicated to ensuring that they have the right knowledge, skills and motivation to work effectively.

The IIP assessor reported that BODC's key strengths include

• Continued organisational planning — including consultation and input from employees
• Effective management support at all levels across the organisation
• An exemplary record of staff learning and personal development activities — including making full use of in-house training opportunities and mentoring
• A positive organisational awareness of health and wellbeing initiatives
• A good team environment with staff feeling valued and appreciated for their efforts

The report highlighted areas of good practice that were clearly beyond the Standard and suggested a few minor development points. An internal team has been formed to look at these suggestions. IIP is a continuous process and we are likely to be reviewed again in 2014.

Data management for the ANDREX and DIMES programmes

The British Oceanographic Data Centre (BODC) announces the launch of the data management pages for the Antarctic Deep Water Rates of Export (ANDREX), and the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) programmes.

Icebergs in the Southern Ocean ©

ANDREX is a UK research programme investigating the role of the Weddell Gyre in the Meridional Overturning Circulation (MOC) and its influence on deep ocean properties. The research concentrates on water mass exchange between the Weddell Gyre and the rest of the Southern Ocean, and the manner in which this process affects the formation of Antarctic Bottom Water (AABW).

DIMES is a joint UK-US research programme that aims to enhance our understanding of Southern Ocean mixing processes. Climate models are highly sensitive to the representation of mixing in the southern limb of the MOC, within the Southern Ocean. The DIMES project aims to constrain these mixing processes, potentially improving the accuracy of climate predictions.

BODC data management pages provide background information about the research programmes, as well as inventories of cruises and associated datasets. Links to cruise tracks and cruise reports are also available. They also provide information about data submission and delivery, and BODC's role in the programme.

Our data management pages are designed to promote data sharing and collaboration between programme participants and the wider scientific community.

GEBCO Web Map Service (WMS)

On behalf of the General Bathymetric Chart of the Oceans (GEBCO) community, BODC has developed a WMS of the GEBCO_08 Grid — a global gridded bathymetric data set.

The WMS provides a means of accessing geo-referenced map images over the internet, which can be viewed in a web browser, incorporated in your own web applications or displayed in various geographic Information System (GIS) mapping packages.

Viewing the GEBCO WMS through a web browser ©

Supported service requests

• GetCapabilities
  
  GetCapabilities request for the GEBCO_08 Grid WMS
  This request returns information about the layers contained in the service in the form of an XML file (you may need to save this to view the information).
  

• GetMap
  
  GetMap request for the GEBCO_08 Grid WMS
  This request returns a map. Using the information given in the GetCapabilities request, the user can specify parameters such as the geographic extent of the map and the size of the returned image.
  

Historical sea level data now available

The British Oceanographic Data Centre (BODC) announces the availability of historical sea level data from charts and ledgers, made possible with funding from the Marine Environmental Data and Information Network (MEDIN), matched by BODC funds.

7 - 9 December 1901 - Belfast tide gauge chart. ©

BODC was in possession of several large historic sea level datasets in the form of scanned images of tide gauge charts and ledgers. These images have been added to the National Oceanographic Database (NODB) and are now freely available to registered users (subject to a licence agreement).

These scanned images are from eight tide gauge sites around the UK. The ledgers for Sheerness contain some of the earliest records (1870 onwards) of sea level data in the UK. Other ledgers came from the Mersey Docks and Harbour Company, and include several sites around Liverpool. The tide gauge charts are from Belfast.

Long-term sea level records have a wide range of scientific and practical applications. They are important to climate change studies (to give an indication of sea level rise), operational oceanography (looking at storm surges and tides) and civil engineering (flood defences) amongst others.

Argo float goes on and on

The oceans have a major influence on our climate system and cover 70% of the Earth's surface; yet relatively little is known about them. To improve our understanding vital data from previously data-sparse ice-free deep ocean areas is being collected by Argo - an international programme which was established in 2000.

In 2007, Argo achieved its aim to create a global array of over 3000 profiling floats; these provide about 100,000 observations each year.

One UK float, deployed in North Atlantic during October 2005, has completed 187 cycles and is approaching a complete loop of the North Atlantic sub-polar gyre - a large, permanent, circular rotation of ocean water.

The float followed the continental shelf edge around the Greenland and Newfoundland coast before heading east at 50° N. ©

The float continues to supply good profiles and application of the Owens and Wong (2009) calibration method reveals no significant sensor drift over its lifetime. More details of its voyage and the data it has collected are provided below.

• October 2005 — a Apex float WMO# 6900388 is deployed at 61° 15.6' N, 20° 0.6' W.
  The float operates a 10 day cycle, whereby it drifts for 9 days at a depth of 1000 m to provide circulation information before descending to a depth of 2000 m. Once it reaches 2000 m it begins an ascent to the sea surface, as it rises it measures the water temperature, salinity and pressure. At the surface it transmits the data it has collected to a receiving station via satellite and descends to a depth of 1000 m, to repeat the cycle.
• Spring 2007 (1) — the float passes the southern tip of Greenland and encounters its first injection of cold and fresh water into surface layers. This water originates in the Arctic and despite its low temperature remains buoyant due to its low salt content.
• January 2008 (2) — a similar cold and fresh water surface event is seen, however by this time the float has crossed the Labrador Sea and is following the Newfoundland continental shelf. During this period it travels up to 200 km between its 10 day cycles, which equates to an average speed of 20 cm s^-1 whilst drifting at a depth of 1000 m.
• February/March 2008 (3) — the floats data shows clear evidence that the upper 2000 m of the water column are well mixed, with both temperature and salinity remaining more or less constant. This seasonal deepening of the mixed layer, due to winter storms, is present but not so obvious in the data from the other years.
• Autumn 2008 (4) — the float meets the northern boundary of the Gulf Stream and is deflected eastwards.
• Autumn 2008 onwards (4+) — the float's increasing meandering path and the fleeting encounters with warm and cold water features as it crosses the eddy field illustrates the Gulf Stream's energetic and unstable flow. Although there is always a seasonal signal present in surface water temperatures, during the floats journey at the boundary of the Gulf Stream a more chaotic signal is superimposed due to interaction with the fringes of the warmer current.

Potential temperature (top) and salinity (bottom) as measured by float WMO# 6900388 during its voyage. ©

The overall journey helps illustrate the circulation features in the North Atlantic. In particular the narrow, linear flow around the north of the basin which contrasts with the turbulent progress of the Gulf Stream in the south. Full size and additional data plots are also available in an Adobe PDF   (2 MB) document.

With over 3000 floats active at any one time, it is inevitable that paths may cross. The final plot shows the path of our float (red) when compared with an Argo Canada float (blue). These are overlain on an annually averaged temperature colour map at 1000 m depth supplied by the UK Met Office FOAM hindcast model.

UK float WMO#6900388 (red) and Canadian float WMO#4900628 (blue) trajectories. ©

It appears that our float has followed the north-western arm of the North Atlantic current and may commence a second circuit. Whereas the Canadian float has taken an alternative route traveling up the Rockall Trough, another main arm of the current, which carries warm water toward Norway and Polar regions.


References
Owens W.B., Wong A.P.S., 2009. An improved calibration method for the drift of the conductivity sensor on autonomous CTD profiling floats by theta-s climatology, Deep-Sea Research Part I: Oceanographic Research Papers, 56(3), 450-457.

Schlitzer R., 2010. Ocean Data View (ODV)

The British Oceanographic Data Centre (BODC) acts as the data centre for UK floats in the Argo programme, regardless of their location. We also act as the Regional Data Centre for the Southern Ocean in collaboration with the Commonwealth Scientific & Industrial Research Organisation (CSIRO), Australia.