Meteorologists can no longer view the Earth as an isolated system. Both long-term climate changes and day-to-day weather show links with the Sun`s activity. Scientists therefore study the nature of those links intensely. With data from ESA`s spaceprobes SOHO, Cluster, and Ulysses, we now have the information we need to solve the mystery of how the Sun`s activity affects the climate here on Earth. This study is the first step in setting up a new type of weather forecast - the space-weather bulletin.
For the Sun to affect the Earth`s weather, the Sun`s behaviour must vary in some way. At visible wavelengths, however, the Sun is remarkably constant. Satellite data show that there are dramatic changes going on beyond this narrow range. For example, the Sun emits a `wind` of charged particles and we know that this wind is variable. The ultraviolet radiation released by the Sun also varies. Studying the interaction between solar variability and the Earth environment is a science known as `space weather`.
This solar variability is caused by the ever-changing magnetic behaviour of the Sun. The Sun`s magnetic behaviour changes on an 11-year cycle, passing from `solar minimum` to `solar maximum`. At the peak of this cycle, one of which occurred last year, the solar wind is stormy because explosions on the Sun`s surface catapult particles outwards with an increased intensity. The energy released during such explosions can be up to one thousand million megatonnes (or 66 thousand million times the energy released by the Hiroshima atomic bomb). Such events are also the source of the variable ultraviolet emissions.
ESA`s solar fleet is observing these phenomena very carefully and from several points in space. The joint ESA/NASA spaceprobe, the Solar and Heliospheric Observatory (SOHO), is constantly watching the Sun, monitoring this activity. The solar wind gusts buffet the magnetic field of the Earth. ESA`s quartet of satellites, Cluster, monitors these effects close to Earth while Ulysses patrols the Sun in a tilted orbit, well away from the plane of the planets, to get a more `global` view of the solar wind.
Alexi Glover | alfa
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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.
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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...
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