Research: Oceanic Records of Global Climate Change
The broad objective of my research is to understand how and why the chemical composition of the oceans and atmospheric carbon dioxide concentrations and global temperature have has changed through time. The oceanic record is central to monitoring and interpreting past climate change. Because the oceans are such a large carbon reservoir, fluctuations in CO2, and hence global temperature, are intimately linked to ocean composition. The factors which control past ocean chemistry are complex and methods involving multiple tracers of past ocean chemistry are the key to understanding them. My main approach is to proxy seawater composition using trace metal and isotopic contents of the carbonate shells of marine microfossils: planktonic and benthic foraminifera. I work with a group of postdocs, research students and technicians, and collaborate with scientists in Cambridge, the UK and worldwide, on a number of research projects, examples of which are:
- Ocean temperatures of the oceans over glacial-interglacial and during rapid climate transitions within the Quaternary and over Cenozoic timescales based on a novel chemical thermometer using the Mg contents of foraminifera shells recovered from oceanic sediment cores; and links to changes in ocean circulation and records of air temperature and CO2 from ice cores.
- Ocean carbonate cycles within the Pleistocene and carbonate saturation state of the oceans compared with changing CO2; how the preservation history of CaCO3 in the deep ocean is affected by changing modes of ocean circulation relationship to internal and external reorganisation of carbon reservoirs.
- Ocean acidification: controls on calcification of marine organisms and their sensitivity to past and future changes in temperature and ocean pH. This research includes studies of marine calcification in response to glacial-interglacial changes in carbon dioxide, links with modern field studies and comparison with instrumental records.
- The role of the Southern Ocean in climate change, linking oceanic and ice core records; data - model comparisons of stable isotopes, temperature and carbonate maps as part of QUEST programme.
Older Publications by Prof Harry Elderfield
Last updated on 22-Jun-10 10:24