An animated illustration of magnetospheric waves, in light blue. At the front of the magnetosphere, these waves appear to be still. Credit: Martin Archer/Emmanuel Masongsong/NASA
Energy from the solar wind engaging with the magnetospheric bubble around Earth creates waves of energy that appear to stand still.
This new finding, from research led by Imperial researchers, improves our understanding of the conditions around Earth that contribute to space weather, which can affect our innovation from interactions satellites in orbit to power lines on the ground.
The Sun launches a stream of charged particles called the solar wind. On the Earths surface, we are secured from this barrage by the magnetosphere– a bubble produced by the Earths electromagnetic field.
When the solar wind hits the magnetosphere, waves of energy are transferred along the border between the 2. Scientists thought the waves should ripple in the instructions of the solar wind, but the brand-new study, released just recently in Nature Communications, exposes some waves do just the opposite.
Standing waves
Previously, lead researcher Dr. Martin Archer, from the Department of Physics at Imperial, and his coworkers established the magnetospheres limit vibrates like a drum. When a drumstick-like pulse from the solar wind strikes the very front of our magnetospheric bubble, waves race toward Earths magnetic poles and get reflected back.
The most recent work considers the waves that form throughout the entire surface area of the magnetosphere, utilizing a mix of designs and observations from NASAs THEMIS (Time History of Events and Macroscale Interactions throughout Substorms) satellites.
The scientists discovered when solar wind pulses strike the magnetosphere, the waves that form not just race back and forth along Earths field lines, however likewise take a trip against the solar wind.
Film of the simulation results at the equator (left) and midday meridian (right). The border of the magnetosphere (black) relocations due to surface waves, which compresses (red) or rarefies (blue) the magnetosphere. The oscillations have actually likewise been transformed into accompanying audio.
The team used models to show how the energy of the wind coming from the Sun and that of the waves breaking it might cancel each other out, creating standing waves that involve a great deal of energy however appear to go nowhere.
Dr. Archer stated: “Its similar to what takes place if you attempt walking up a downwards escalator. Its going to appear like youre not moving at all, despite the fact that youre putting in loads of effort.”
These standing waves can continue longer than those that travel with the solar wind. That means theyre around longer to speed up particles in near-Earth space, resulting in possible effects in areas like Earths radiation belts, aurora, or ionosphere.
The researchers likewise say that standing waves might take place somewhere else in deep space, from the magnetospheres of other planets to the peripheries of black holes.
Waves of sound
The researchers likewise equated the electromagnetic signals from the THEMIS satellites into audio, allowing us to listen to the sounds of the waves taking a trip across the magnetospheric boundary.
Compressions and rarefactions of the magnetosphere as determined by the THEMIS satellites transformed into audible sound.
Dr. Archer included: “While in a simulation we can see whats going on everywhere, satellites can just determine these waves where they are giving us only time-series, wiggly lines. This sort of information is in fact best matched to our sense of hearing than sight, so listening to the data can typically provide us a more instinctive concept of whats going on.
” You can hear the deep breathing sound of the standing surface area waves persist throughout, increasing in volume as each pulse hits. Greater pitched sounds, connected with other types of waves, do not last nearly as long.”
For more on this research, see Surprising Standing Waves at Edge of Earths Magnetic Bubble Found in NASA Data.
Reference: “Magnetopause ripples going versus the flow type azimuthally fixed surface area waves” by M. O. Archer, M. D. Hartinger, F. Plaschke, D. J. Southwood and L. Rastaetter, 6 October 2021, Nature Communications.DOI: 10.1038/ s41467-021-25923-7.
The limit of the magnetosphere (black) moves due to surface waves, which compresses (red) or rarefies (blue) the magnetosphere.
” Its similar to what happens if you try walking up a downwards escalator. Its going to look like youre not moving at all, despite the fact that youre putting in loads of effort.”– Dr. Martin Archer
An animated illustration of magnetospheric waves, in light blue. At the front of the magnetosphere, these waves appear to be still. Credit: Martin Archer/Emmanuel Masongsong/NASA
— Dr. Martin Archer