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
Hundreds of bubble streams link biology, seismology off Washington's coast
22.03.2019 | University of Washington
Atmospheric scientists reveal the effect of sea-ice loss on Arctic warming
11.03.2019 | Institute of Atmospheric Physics, Chinese Academy of Sciences
DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.
The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
22.03.2019 | Life Sciences
22.03.2019 | Life Sciences
22.03.2019 | Information Technology