As well as being key for the northward transport of heat, the North Atlantic also plays a very important role in the global carbon cycle. Cooling waters and intense biological activity lead to a strong reduction in carbon dioxide concentrations at the surface. CO2 is then absorbed from the atmosphere to make up the deficit, with human-derived carbon (from fossil fuel burning, land-use change, concrete production etc) being absorbed at the same time. This ocean ‘sink’ vastly slows down the increase of CO2 levels in the atmosphere caused by human activities. It’s thus important to understand the processes and drivers of how this happens now so we can better predict how it will behave in the future.
|A volunteer observing ship, the M/V Santa Maria, travelling between the UK & the Caribbean|
This is where the new biogeochemical sensors and sampling technologies being deployed across the RAPID mooring array are seeking to fill the gaps. As part of the Atlantic BiogeoChemical Fluxes program (www.rapid.ac.uk/abc), oxygen, pH and pCO2 sensors are being installed alongside autonomous samplers collecting water to be analysed for dissolved inorganic carbon, total alkalinity, inorganic nutrients (phosphate, nitrate and silicate) and organic nitrogen.
|The biogeochemical sensor & sampler suite ready for deployment at the Mid-Atlantic Ridge|
In the next part, we’ll look at bit more at the new technologies being deployed to add a biogeochemical dimension to the RAPID array.
Written by Pete