Nav: Home

Magnetic pumping pushes plasma particles to high energies

November 05, 2018

PORTLAND, Ore.--As you walk away from a campfire on a cool autumn night, you quickly feel colder. The same thing happens in outer space. As it spins, the sun continuously flings hot material into space, out to the furthest reaches of our solar system. This material, called the solar wind, is very hot close to the sun, and we expect it to cool quickly as it streams away. Satellite observations, however, show this is not the case--the solar wind cools as it streams out, but stays hotter than expected. There must be some additional way the solar wind heats up as it travels from the sun to Earth.

The solar wind is not like a calm summer breeze. Instead, it is a roiling, chaotic mess of turbulence and waves. There is a lot of energy stored in this turbulence, so scientists have long thought that it heats the solar wind. There is, however, a big issue--the heating expected from turbulence is not the heating observed.

Scientists at the University of Wisconsin - Madison have a new idea about what heats the solar wind, a theory called magnetic pumping. "If we imagine a toy boat on a lake, waves move the toy boat up and down. However, if a rubber duck comes by and hits the toy boat it can get out of sync with the waves. Instead of moving along with the waves the toy boat is pushed by the waves, making it move faster. Magnetic pumping works the same way--waves push the particles in the solar wind," said Emily Lichko, a graduate student who will be presenting her work at the American Physical Society's Division of Plasma Physics meeting in Portland, Ore.

A special feature of the idea is that all the particles in the solar wind should be affected by magnetic pumping, including the most energetic. Heating due to turbulence has an upper limit, but the new idea allows for heating of even extremely fast particles.

Where the solar wind hits Earth's magnetic field is a perfect place to look for magnetic pumping in nature. Satellites from NASA's Magnetospheric Multiscale (MMS) mission can measure the velocities of particles in incredible, unprecedented detail. The data shows evidence of magnetic pumping.

This research, funded by NASA, the National Science Foundation, and the Department of Defense, is important because if energetic particles reach the space near Earth, they can damage satellites, harm astronauts, and even interrupt military communication. Understanding how these particles are energized, and what happens to them as they travel from the sun to Earth, will someday help scientists develop methods to better protect us from the effects of these particles. Additionally, it is possible that magnetic pumping could also be happening beyond the solar wind in places like the sun's atmosphere, the interstellar medium, or supernova explosions. This research has the potential to shed light not just on the solar wind, but on how particles throughout the universe are heated.
-end-


American Physical Society

Related Solar Wind Articles:

New research helps explain why the solar wind is hotter than expected
When the sun expels plasma, the solar wind cools as it expands through space -- but not as much as the laws of physics would predict.
Solar wind samples suggest new physics of massive solar ejections
A new study led by the University of Hawai'i (UH) at Mānoa has helped refine understanding of the amount of hydrogen, helium and other elements present in violent outbursts from the Sun, and other types of solar 'wind,' a stream of ionized atoms ejected from the Sun.
Supporting structures of wind turbines contribute to wind farm blockage effect
Much about the aerodynamic effects of larger wind farms remains poorly understood.
Parker Solar Probe traces solar wind to its source on sun's surface: coronal holes
New data from the Parker Solar Probe, which got closer to the sun than any other spacecraft, allowed physicists to map the source of a major component of the solar wind that continually peppers Earth.
Closest-ever approach to the sun gives new insights into the solar wind
The Parker Solar Probe spacecraft, which has flown closer to the sun than any mission before, has found new evidence of the origins of the solar wind.
SwRI-built instrument confirms solar wind slows farther away from the Sun
Measurements taken by the Solar Wind Around Pluto (SWAP) instrument aboard NASA's New Horizons spacecraft are providing important new insights from some of the farthest reaches of space ever explored.
Switching to solar and wind will reduce groundwater use
IIASA researchers explored optimal pathways for managing groundwater and hydropower trade-offs for different water availability conditions as solar and wind energy start to play a more prominent role in the state of California.
Solar and wind energy preserve groundwater for drought, agriculture
A Princeton University-led study in Nature Communications is among the first to show that solar and wind energy not only enhance drought resilience, but also aid in groundwater sustainability.
Researchers recreate the sun's solar wind and plasma 'burps' on Earth
A new study by University of Wisconsin-Madison physicists mimicked solar winds in the lab, confirming how they develop and providing an Earth-bound model for the future study of solar physics.
Spacecraft measurements reveal mechanism of solar wind heating
Queen Mary University of London has led a study which describes the first direct measurement of how energy is transferred from the chaotic electromagnetic fields in space to the particles that make up the solar wind, leading to the heating of interplanetary space.
More Solar Wind News and Solar Wind Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.