Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




SOLAR SCIENCE
Plasma plumes help shield Earth from damaging solar storms
by Jennifer Chu for MIT News
Boston MA (SPX) Mar 10, 2014


File image.

The Earth's magnetic field, or magnetosphere, stretches from the planet's core out into space, where it meets the solar wind, a stream of charged particles emitted by the sun. For the most part, the magnetosphere acts as a shield to protect the Earth from this high-energy solar activity.

But when this field comes into contact with the sun's magnetic field - a process called "magnetic reconnection" - powerful electrical currents from the sun can stream into Earth's atmosphere, whipping up geomagnetic storms and space weather phenomena that can affect high-altitude aircraft, as well as astronauts on the International Space Station.

Now scientists at MIT and NASA have identified a process in the Earth's magnetosphere that reinforces its shielding effect, keeping incoming solar energy at bay.

By combining observations from the ground and in space, the team observed a plume of low-energy plasma particles that essentially hitches a ride along magnetic field lines - streaming from Earth's lower atmosphere up to the point, tens of thousands of kilometers above the surface, where the planet's magnetic field connects with that of the sun. In this region, which the scientists call the "merging point," the presence of cold, dense plasma slows magnetic reconnection, blunting the sun's effects on Earth.

"The Earth's magnetic field protects life on the surface from the full impact of these solar outbursts," says John Foster, associate director of MIT's Haystack Observatory.

"Reconnection strips away some of our magnetic shield and lets energy leak in, giving us large, violent storms. These plasmas get pulled into space and slow down the reconnection process, so the impact of the sun on the Earth is less violent."

Foster and his colleagues publish their results in this week's issue of Science. The team includes Philip Erickson, principal research scientist at Haystack Observatory, as well as Brian Walsh and David Sibeck at NASA's Goddard Space Flight Center.

Mapping Earth's magnetic shield
For more than a decade, scientists at Haystack Observatory have studied plasma plume phenomena using a ground-based technique called GPS-TEC, in which scientists analyze radio signals transmitted from GPS satellites to more than 1,000 receivers on the ground.

Large space-weather events, such as geomagnetic storms, can alter the incoming radio waves - a distortion that scientists can use to determine the concentration of plasma particles in the upper atmosphere. Using this data, they can produce two-dimensional global maps of atmospheric phenomena, such as plasma plumes.

These ground-based observations have helped shed light on key characteristics of these plumes, such as how often they occur, and what makes some plumes stronger than others. But as Foster notes, this two-dimensional mapping technique gives an estimate only of what space weather might look like in the low-altitude regions of the magnetosphere. To get a more precise, three-dimensional picture of the entire magnetosphere would require observations directly from space.

Toward this end, Foster approached Walsh with data showing a plasma plume emanating from the Earth's surface, and extending up into the lower layers of the magnetosphere, during a moderate solar storm in January 2013. Walsh checked the date against the orbital trajectories of three spacecraft that have been circling the Earth to study auroras in the atmosphere.

As it turns out, all three spacecraft crossed the point in the magnetosphere at which Foster had detected a plasma plume from the ground. The team analyzed data from each spacecraft, and found that the same cold, dense plasma plume stretched all the way up to where the solar storm made contact with Earth's magnetic field.

A river of plasma
Foster says the observations from space validate measurements from the ground. What's more, the combination of space- and ground-based data give a highly detailed picture of a natural defensive mechanism in the Earth's magnetosphere.

"This higher-density, cold plasma changes about every plasma physics process it comes in contact with," Foster says. "It slows down reconnection, and it can contribute to the generation of waves that, in turn, accelerate particles in other parts of the magnetosphere. So it's a recirculation process, and really fascinating."

Foster likens this plume phenomenon to a "river of particles," and says it is not unlike the Gulf Stream, a powerful ocean current that influences the temperature and other properties of surrounding waters. On an atmospheric scale, he says, plasma particles can behave in a similar way, redistributing throughout the atmosphere to form plumes that "flow through a huge circulation system, with a lot of different consequences."

"What these types of studies are showing is just how dynamic this entire system is," Foster adds.

.


Related Links
Massachusetts Institute of Technology
Solar Science News at SpaceDaily






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SOLAR SCIENCE
Hinode Views Sunspot Activity
Pasadena CA (JPL) Mar 06, 2014
Active Region 11967 consisted of a major sunspot that released numerous solar flares in early 2014. Above is an image taken by the Solar Optical Telescope (SOT) aboard Hinode in the Calcium II H line on Feb. 7, 2014 at 16:09 UT. Below is a wider view of Active Region 11967 as seen by SDO on Feb.12, 2014, at 01:35 UT. By studying the sun's magnetic field, scientists hope to shed new l ... read more


SOLAR SCIENCE
Russia to launch three lunar rovers from 2016 to 2019

Control circuit malfunction troubles China's Yutu

China's Lunar Lander Still Operational

China Focus: Uneasy rest begins for China's troubled Yutu rover

SOLAR SCIENCE
Opportunity Mars Rover Exploring Murray Ridge Area

Mars Rover Oppportunity Crushing Rocks With Wheels

Relay Radio on Mars-Bound NASA Craft Passes Checkout

Robotic Arm Crushes Rock for Study

SOLAR SCIENCE
Bright pulses of light could make space veggies more nutritious

Under shadow of spy scandal, Merkel, Cameron head to tech fair

Committee Democrats Emphasize Need for Human Space Exploration Roadmap

NASA Commercial Crew Partners Complete Space System Milestones

SOLAR SCIENCE
China to launch first "space shuttle bus" this year

China expects to launch cargo ship into space around 2016

China capable of exploring Mars

Feature: The "masters" behind China's lunar rover Jade Rabbit

SOLAR SCIENCE
NASA says US-Russia space ties 'normal'

Cancer Targeted Treatments from Space Station Discoveries

Cosmonauts on space station to turn teacher for Russian students

Space suit leak happened before, NASA admits

SOLAR SCIENCE
Payload prep continues for Arianespace Soyuz for Sentinel-1A

Russia to Start Building New Manned Rocket Launch Pad in 2015

New Vostochny space center a key priority for Russian Far East

'Mission of Firsts' Showcased New Range-Safety Technology at NASA Wallops

SOLAR SCIENCE
'Dimer molecules' aid study of exoplanet pressure, hunt for life

A small step toward discovering habitable earths

What Would A Rocky Exoplanet Look Like? Atmosphere Models Seek Clues

Super-Earth' may be dead worlds

SOLAR SCIENCE
South Africa's nano-satellite encounters space debris

Ecliptic RocketCam Captures Sirius Antenna Deployment In Geo Orbit

Ultra-fast laser spectroscopy lights way to understanding new materials

Aerojet Rocketdyne Provides Propulsion For GPM Satellite




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.