SOLIS observatory gives new insights into space weather

Jul 11, 2013

(Phys.org) —Shifts in the magnetic field just above the surface of the Sun lead to liftoff of interplanetary "space storms," according to new results from the Synoptic Optical Long-Term Investigation of the Sun (SOLIS) instrument. The results were presented by California State University, Northridge, physics and astronomy professor Debi Prasad Choudhary at this week's 44th meeting of the Solar Physics Division of the American Astronomical Society in Bozeman, Mont.

Understanding space weather and the enormous "storms" that cause it, called (CMEs), is a major goal of current solar research. SOLIS, built by the National Solar Observatory and operated at Kitt Peak, Ariz., is a special-purpose telescope that can image the magnetic field at the surface of the Sun and, simultaneously, in the layer just above the surface, called the "chromosphere."

CMEs are enormous clouds of material that are far larger than the Sun, can weigh billions of tons, and zoom through space at speeds up to four million miles per hour. When CMEs impact the Earth's , they cause effects that affect many aspects of life on Earth, including the aviation industry, , terrestrial and astronauts. CMEs that are associated with are the most violent and the most important to predict. Decades of observations of these magnetic explosions on the Sun have produced a wealth of information, yet predicting the exact timing of their occurrence is a challenge for solar astronomers.

"We were trying to find a precursor to solar flares that shoot CMEs into space," said Choudhary. "With magnetic field measurements at multiple locations in the Sun's atmosphere from SOLIS, we were able to show that changes in the vertical structure of the magnetic field lead to flares and CMEs."

Choudhary found that, in the site of a CME-bearing flare over a sunspot, the vertical magnetic field structure would change in an identifiable way: the vertical gradient would steepen, and small scale motions of magnetized regions would become stronger and faster. There would be multiple magnetic clouds with different speeds and magnetic field properties.

Not all flares are associated with the precursor, but in four cases where Choudhary saw the complex material flow and magnetic structure, a CME and flare followed shortly.

SOLIS works by measuring the detailed structure of spectral absorption lines, particular narrow ranges of color that are missing from sunlight. In the presence of a magnetic field, the absorption lines change their structure slightly, and this effect can be used to measure the remotely. Because different spectral lines are formed at different altitudes in the solar atmosphere, it is possible to measure at several altitudes simultaneously.

K. D. Leka, senior research scientist with NorthWest Research Associates, said "studying the chromosphere using the diagnostics that are available from the SOLIS facility could hold a wealth of information regarding CME precursors."

Explore further: Video gives astronaut's-eye view inside NASA's Orion spacecraft

Provided by California State University, Northridge

5 /5 (1 vote)
add to favorites email to friend print save as pdf

Related Stories

Sun erupts with a CME toward Earth and Mercury

Jul 10, 2013

On July 9, 2013, at 11:09 a.m. EDT, the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon that can send billions of tons of particles into space that can reach Earth one to ...

Solar tsunami used to measure Sun's magnetic field

Jul 11, 2013

(Phys.org) —A solar tsunami observed by NASA's Solar Dynamics Observatory (SDO) and the Japanese Hinode spacecraft has been used to provide the first accurate estimates of the Sun's magnetic field.

Sun emits a solstice CME

Jun 21, 2013

On June 20, 2013, at 11:24 p.m., the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon that can send billions of tons of particles into space that can reach Earth one to ...

NASA's STEREO detects a CME from the sun

May 17, 2013

On 5:24 a.m. EDT on May 17, 2013, the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon that can send billions of tons of solar particles into space that can reach Earth ...

Sun produces two CMEs

Feb 07, 2013

In the evening of Feb. 5, 2013, the sun erupted with two coronal mass ejections or CMEs that may glance near-Earth space. Experimental NASA research models, based on observations from the Solar Terrestrial ...

SDO observes mid-level solar flare

May 22, 2013

UPDATE 16:30 p.m. EDT: The M7-class flare was also associated with a coronal mass ejection or CME, another solar phenomenon that can send billions of tons of particles into space. While this CME was not Ea ...

Recommended for you

SDO captures images of two mid-level flares

Dec 19, 2014

The sun emitted a mid-level flare on Dec. 18, 2014, at 4:58 p.m. EST. NASA's Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts ...

Why is Venus so horrible?

Dec 19, 2014

Venus sucks. Seriously, it's the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you ...

Image: Christmas wrapping the Sentinel-3A antenna

Dec 19, 2014

The moment a team of technicians, gowned like hospital surgeons, wraps the Sentinel-3A radar altimeter in multilayer insulation to protect it from the temperature extremes found in Earth orbit.

Video: Flying over Becquerel

Dec 19, 2014

This latest release from the camera on ESA's Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.