Matthew Schmidt, associate professor of oceanography, and Ping Chang, professor of oceanography and atmospheric science and director of the Texas Center for Climate Studies, along with colleagues from Georgia Tech, Princeton, the Woods Hole Oceanographic Institution, the University of Cambridge and Germany’s University of Bremen, have had their findings published in the latest issue of Nature Geoscience.
To make this discovery, the researchers studied the chemistry of shells produced by benthic foraminifera, single-celled organisms that live near the sea floor. These benthic foraminifera were collected from sediment cores recovered from the margins of the Florida Straits. By studying the oxygen isotope composition of the shells, the researchers were able to reconstruct past changes in Florida Current transport, which is directly related to the strength of the global conveyor belt circulation.
Researchers have known for years about Heinrich Events, periods of extreme cold in the North Atlantic. These events were named for the geologist who first discovered them, Hartmut Heinrich. They occurred during the last ice age when immense icebergs broke loose from glaciers, and as they melted, deposited ice rafted debris on the sea floor. Six of these Heinrich events have been identified, and they are known as H1 through H6.
“While there is evidence that the last Heinrich Event that occurred around 17,000 years ago was indeed caused by a dramatic reduction in the ocean’s conveyor belt circulation, our new reconstruction of ocean circulation patterns during some earlier Heinrich Events, that occurred during the last ice age between 20,000 and 30,000 years ago, did not reveal significant changes in ocean circulation,” Schmidt explains. “Nevertheless, these Heinrich Events were experienced worldwide, so they must have been transmitted via the atmosphere.”
Schmidt says that the study “has important implications for our understanding of the mechanisms of abrupt climate change in the past. The more we know about how climate changed in the past, the better prepared we will be for predicting future climate variability.”
Matthew Schmidt | Newswise
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Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
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...
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