Heidelberg researchers studied the dynamics of the Mediterranean outflow through the Straits of Gibraltar – impact on global ocean circulation
As a result of global warming, more extremely salty water masses from the Mediterranean will be flowing into the North Atlantic through the Straits of Gibraltar. This was the conclusion of researchers from Heidelberg University working with an international research team to investigate the dynamics of Mediterranean outflow.
According to Dr. André Bahr from the Institute of Earth Sciences, this process could counterbalance the predicted drop in the North Atlantic’s salt content. Experts believe that the desalination brought on by massive melt waters from the Arctic and Greenland will significantly affect global ocean circulation and possibly weaken the Gulf Stream. The findings were published in the journal “Geology”.
To better understand the dynamics of the Mediterranean outflow, the researchers analysed its behaviour under different climatic conditions in the geologic past. They studied core samples from the continental shelf off of southern Spain and Portugal obtained through the International Ocean Discovery Program. “The data show that the Mediterranean current was subject to massive and in some cases extremely abrupt fluctuations over the last 150,000 years,” says Dr. Bahr.
The Heidelberg researcher explains that the strength of the current depends mainly on the intensity of the African monsoon, as is evident from the origin of the water that flows into the Atlantic. It derives for the most part from the eastern Mediterranean, where hot and dry conditions raise the salt content in the surface water.
In winter these water masses cool, become denser and flow west at greater depths, where they leave the Mediterranean through the Straits of Gibraltar. If strong monsoons in Northeast Africa increase the inflow of fresh water, the formation of this dense, salty water is inhibited and the outflow of Mediterranean water into the Atlantic weakened along with it.
Conversely, the very dry conditions in the eastern Mediterranean that current climate models strongly predict will boost the salt content in the surface waters and thus strengthen the current from the Mediterranean.
“A comparison of the data we derived on the strength of the ocean circulation in the recent geologic past indicates that a strong Mediterranean outflow and the increased inflow of salt into the Atlantic at the end of the last warm cycle 120,000 years ago actually had a stabilising effect.
This is because the circulation is significantly driven by the contrasts in salt content in the different water masses,” explains André Bahr. For this reason, the geoscientist believes that tropical and subtropical climate changes and their impact on oceanography should figure more prominently in climate prognoses. Researchers from Germany, the Netherlands, Japan, Spain, Portugal and Great Britain contributed to the study.
A. Bahr, S. Kaboth, F. Jiménez-Espejo, F. Sierro, A. Voelker, L. Lourens, U. Röhl, G. Reichart, C. Escutia, F. Hernández-Molina: Persistent monsoonal forcing of Mediterranean Outflow Water dynamics during the late Pleistocene. Geology (published online on 24 September 2015), doi: 10.1130/G37013.1
Dr. André Bahr
Institute of Earth Sciences
Phone +49 6221 54-6062
Communications and Marketing
Phone +49 6221 54-2311
Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy