The findings, reported in this week’s edition of the international journal Science (30 June 2006), prove for the first time that sudden North American ‘lake bursts’ slowed ocean circulation and cooled the climate approximately 8200 years ago. The groundbreaking research increases our understanding of the complex link between ocean circulation and climate change and highlights the sensitivity of the Atlantic overturning circulation to freshwater forcing.
Christopher Ellison and Dr Mark Chapman, of UEA’s School of Environmental Sciences, and Dr Ian Hall, of Cardiff University’s School of Earth, Ocean and Planetary Sciences, investigated whether there was a connection between the catastrophic freshwater release from glacial lakes in North America, ocean circulation changes and the dramatic cooling seen in many climate records approximately 8200 years ago. The research team studied a sediment core taken from the seabed of the North Atlantic.
“The core contains sediments representing the warm interval since the last Ice Age,” said Christopher Ellison of the University of East Anglia. “The sediment includes a variety of small animals called foraminifera that record surface water conditions in their shells when living. We analysed changes in the abundance of different species of foraminifera and the chemistry of the shells to examine past patterns of climate change. We also analysed the sediment grain size to gauge the speed of deep ocean currents and therefore the strength of ocean circulation.”
The new findings provide direct evidence of both the freshwater forcing and the climate response.
“The 8200-year-old event is the most recent abrupt climate change event and by far the most extreme cooling episode in the last 10,000 years, but up until now we knew comparatively little about its impact, if any, on the ocean circulation,” said Dr Mark Chapman of the University of East Anglia. “Our records show a sequenced pattern of freshening and cooling of the North Atlantic sea surface and an associated change in the deep ocean circulation, all key factors that are involved in controlling the state of northern hemisphere climate.”
Dr Ian Hall of Cardiff University said: “The impact of large-scale pulsed inputs of freshwater on ocean circulation and climate during the time of the last Ice Age are well documented, but our results clearly demonstrate that these sorts of abrupt reorganisations also can occur during periods of warm climate. These findings have important implications for future research because they aid our understanding of the magnitude of forcing involved in rapid climate changes and the mechanisms involved. This provides a useful target for assessing the models that are used to predict future patterns of climate change”.
The study was supported by the Natural Environment Research Council and is part of a national programme, RAPID, aimed at improving scientist’s ability to quantify the probability and magnitude of future rapid change in climate.
Press Office | alfa
Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University
Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy