Details of Award
NERC Reference : NE/C001060/1
A seasonally resolved record of the 13C Suess Effect in the NE Atlantic, 1948-present
Grant Award
- Principal Investigator:
- Professor W Austin, University of St Andrews, School of Geography and Geosciences
- Co-Investigator:
- Professor M Bird, James Cook University, Earth and Oceans
- Co-Investigator:
- Professor M Edwards, Marine Biological Association, CPR Survey
- Grant held at:
- University of St Andrews, School of Geography and Geosciences
- Science Area:
- Marine
- Atmospheric
- Overall Classification:
- Marine
- ENRIs:
- Global Change
- Science Topics:
- Ocean - Atmosphere Interact.
- Biogeochemical Cycles
- Quaternary Science
- Climate & Climate Change
- Abstract:
- Human activity from land-use change and fossil fuel (coal, oil and gas) burning has resulted in increasing carbon dioxide concentrations in the Earth's atmosphere over the last 200 years. Scientists and governments are concerned about the increasing levels of carbon dioxide because it is an important greenhouse gas, thought to drive global warming. However, only about half of the carbon dioxide produced by these activities remains in the atmosphere, the other half is taken-up (or sequestered) by the oceans, plants on land (the terrestrial biosphere) and, more slowly, by sediments and sedimentary rocks. A significant proportion of the ever-increasing amounts of carbon dioxide introduced into the atmosphere every year through human activity is sequestered by the oceans. Some regions, for example the sub-polar oceans where deep-water is formed, are much more efficient than others, for example the warm sub-tropical oceans, as a sink for atmospheric carbon dioxide. It is therefore essential for scientists to understand where, when and at what rates carbon dioxide is sequestered in the oceans, if the critical role of the oceans in the global carbon cycle is to be fully understood. Only when we understand the operation of the global carbon cycle will we be able to predict how future climate change will respond to greenhouse gas forcing. This proposal aims to improve our understanding of carbon dioxide sequestration by the oceans through the study of carbon isotopes (12C, 13C and 14C). The ratios of these isotopes are changed in nature by several processes. Photosynthesis, for example, causes more of the light isotope 12C to be incorporated so that the organic material formed (e.g. wood) has a 13C-depleted signature. Fossil fuels are also depleted in 13C and when they are burnt they produce carbon dioxide with a 13C-depleted signature. This means that as levels of carbon dioxide have risen during the past 200 years the ratios of 13C/12C in atmospheric carbon dioxide have also changed. We call this the 13C Suess effect, after the scientist who first described the phenomenon. The 13C Suess effect in the ocean occurs because the 13C-depleted carbon dioxide of the atmosphere dissolves and contributes to the dissolved inorganic carbon (DIC) in seawater. Scientists use the changing 12C/13C ratio of DIC in seawater to calculate how much of the 'industrial' carbon dioxide has been sequestered by the oceans. The Sir Alister Hardy Foundation for Ocean Sciences (SAHFOS) at Plymouth maintains a collection of near-surface dwelling microscopic plant (phytoplankton) samples from the North Atlantic Ocean that have been collected using Continuous Plankton Recorders since 1946. Just like trees on land, phytoplankton in the surface ocean photosynthesise and fix carbon from the DIC in seawater. We intend to measure the 12C/13C ratios in these preserved samples of marine phytoplankton, collected at monthly intervals from 1948 to the present, to determine how the oceanic 13C Suess effect changes with time and location around the North Atlantic. In addition, we intend to measure the concentration of the radioactive carbon isotope 14C, which we know increased in abundance during extensive nuclear weapon tests from 1954 to 1962. This so-called 'bomb pulse' provides another very good tracer of ocean-atmosphere exchange processes. The information we hope to generate from this unexploited resource at SAHFOS is truly unique and, in some ways, offers a 'second-chance' for us to look at how the 12C/13C ratio of DIC has changed over the last half century when atmospheric carbon dioxide levels have risen at their most rapid rates.
- NERC Reference:
- NE/C001060/1
- Grant Stage:
- Completed
- Scheme:
- Small Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Small Grants
This grant award has a total value of £31,286
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £17,177 | £827 | £5,380 | £7,902 |
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