Raimund Muscheler is a researcher at the Department of Earth and Ecosystem Sciences at Lund University in Sweden. In the latest issue of the journal Science, he and his colleagues have described how the surface water temperature in the tropical parts of the eastern Pacific varied with the sun’s activity between 7 000 and 11 000 years ago (early Holocene). Contrary to what one might intuitively believe, high solar activity had a cooling effect in this region.
“It is perhaps a similar phenomenon that we are seeing here today”, says Raimund Muscheler. “Last year’s cold winter in Sweden could intuitively be seen to refute global warming. But the winter in Greenland was exceptionally mild. Both phenomena coincide with low solar activity and the sun’s activity probably influences the local climate variations.”
Today there is a lot of debate about whether the sun’s activity could have influenced the earth’s climate over thousands or millions of years.
“The key processes in this influence are still mostly unclear. This is why the present climate models probably do not include the full effect of solar activity”, says Raimund Muscheler.
By reconstructing surface water temperatures from plankton stored in a sediment core taken from the seabed off the west coast of Baja California Sur, Mexico, researchers have now made new findings. The results suggest that solar activity has influenced the sea’s surface water temperature by changing local circulation processes in the sea. Previous studies have shown that the surface water temperature in the tropical Pacific Ocean is linked to atmospheric and seawater circulation through the regional weather phenomena El Niño and El Niña.
“We know that El Niño brings a warmer climate, while El Niña brings a cooler climate in the eastern part of the Pacific Ocean”, says Raimund Muscheler. “If we presume that this connection existed during the early Holocene, this means that there could be a link between solar activity and El Niño/El Niña on long time scales.”
In his research, Raimund Muscheler works to reconstruct previous changes in solar activity by studying how cosmogenic isotopes, for example of beryllium-10 and carbon-14, have been stored in both ice cores and annual rings in trees. Cosmogenic isotopes are formed in the atmosphere as a result of cosmic radiation from space. When solar activity is high, a small amount of the cosmic radiation reaches the atmosphere and thus a small number of cosmogenic isotopes are formed and stored.
“This is the best and most reliable method we have to reconstruct solar activity”, says Raimund Muscheler.
Raimund Muscheler, researcher in quaternary geology, Lund University. Raimund.Muscheler@geol.lu.se, tel. +46 46 222 04 54
Pressofficer Lena Björk Blixt; Lena.Bjork_Blixt@kanslin.lu.se; +46-46 222 7186
Lena Björk Blixt | idw
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy