Friday, 17 October 2008

Rothera Time Series (RaTS) data is now available from the BODC

Through our partnership with the British Antarctic Survey (BAS), the Rothera Oceanographic and Biological Time Series (RaTS) data set is now accessible via the British Oceanographic Data Centre's (BODC) online series request facility.

Currently, over ten years of CTD data are presented. In a few months, moored current meter data will also be made available.

Figure 1 - Rothera Time Series off western coast of the Antarctic Peninsula in the Marguerite Bay.
Figure 2 - A close up of the sampling sites in Marguerite Bay, Antarctica. ©

More about RaTS

The RaTS programme is funded by NERC. It involves the long-term monitoring of a nearshore marine environment in the Antarctic. Its aims are to

  • aid interpretation of the local ecology
  • test a series of hypotheses concerning interactions between surface and deep waters and the environmental forcing of the nearshore environment

Sampling began in January 1997, at a site (Site 1) approximately 4 km from the coast of the BAS station at Rothera. Weather and ice permitting, an upper open hydrographic cast and discrete water sample (at a depth of 15 m) are collected every fifth day during summer and every seventh day during winter.

If Site 1 is inaccessible then the secondary station, Site 2, is occupied; if neither are accessible then a water sample is collected near the wharf at Rothera (Site 3) but no hydrography cast is taken.

Thursday, 9 October 2008

Argo float data products

BODC present an animation of the Forecasting Ocean Assimilation Model (FOAM) ¼° Antarctic output images for potential temperature, salinity and velocity.

Argo float data are assimilated into the FOAM model at the Met Office and provide a significant positive impact. Experiments have shown that the addition of these data reduce error by almost 30%, enabling more accurate forecasts.

Potential temperature from FOAM
Potential temperature from FOAM ©

Data supply chain

  • On surfacing, a float transmits the data collected via satellites to a receiving station.
  • Data are downloaded, quality controlled, encoded and delivered on a daily basis to the Global Telecommunications System (GTS), thus enabling them to be included in various meteorological and oceanographic models.
  • Data are assimilated in to the Forecasting Ocean Assimilation Model (FOAM) at the Met Office.
  • FOAM ¼° Antarctic model output images of potential temperature, salinity and velocity are supplied by the Met Office to BODC at monthly intervals.
  • An animation of the FOAM ¼° Antarctic model output images is presented.

Argo data

Argo, a worldwide programme involving over 30 countries, was established in 2000 to provide regular measurements from previously data-sparse areas throughout ice-free deep-ocean areas to improve our understanding of ocean systems. A global network of over 3000 active profiling floats was achieved in November 2007.

These specialised floats are able to descend and ascend through the water column by changing their buoyancy. As the float rises to the sea surface, it collects temperature, salinity and pressure measurements. The data are vital for monitoring ocean temperature - a key factor in climate change.

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