The spectacular aurora borealis displays that light up the northern nights could be powered by a gigantic "slinky" effect in Earths magnetic field lines, according to research performed at the University of Minnesota. Earths magnetic field resemble a slinky in that when "wiggled," it undulates in waves that travel down the field lines at speeds up to 25 million miles per hour. These waves can pass energy to electrons, accelerating them along the magnetic field lines toward Earth. When the electrons hit atoms in the atmosphere, the atoms become excited and produce the colors of the aurora. Using electric and magnetic field data and images from NASAs POLAR satellite, the researchers showed that energy from such waves is sufficient to power auroras and that statistically, the waves occur in the same locations as auroras--in a ring around the poles. The work will be published in the Jan. 17 issue of Science.
"We dont know exactly what wiggles the field lines, but similar processes could explain the heating of the solar corona [the suns atmosphere], the release of energy during solar flares and the acceleration of the solar wind [a stream of charged particles from the sun]," said physics associate professor John Wygant, second author of the study. "At the edges of sunspots, other researchers have actually seen magnetic field lines waving. Understanding how such waves are caused and how they transmit energy is important to unraveling the complex processes behind larger-scale particle accelerations that occur, for example, in jets of material being ejected from black holes at the centers of galaxies." The papers first author is Andreas Keiling, who headed the study while a doctoral student and, later, a research scientist at the University of Minnesota. He is now at the Center for Space Research on Radiation in Toulouse, France.
The ultimate source of energy for auroras is the solar wind. Flowing with the wind--which is mostly single protons and electrons--is a magnetic field that encounters Earths own field tens of thousands of miles above the planet surface. Earth is like a huge bar magnet, with magnetic field lines coming out near the poles, curving through space, and re-entering near the opposite pole. When the solar winds magnetic field sweeps by, it joins with some of Earths magnetic field lines and stretches them into space on the night side of Earth. The stretching energizes this part of the magnetic field until it suddenly "snaps" away from the solar wind and reconnects with Earth. This process, called reconnection, may send waves rippling through the magnetic field, like wiggling a slinky, said Wygant.
Deane Morrison | EurekAlert!
Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle
22.06.2018 | Technical University of Denmark
Polar ice may be softer than we thought
22.06.2018 | Eberhard Karls Universität Tübingen
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences