Solar Tsunami

Effects of Solar Tsunami

2010-08-03T16:30:00.000-07:00

Two huge explosions on the sun have sent clouds of charged particles to earth

LAST UPDATED 2:40 PM, AUGUST 3, 2010

The earth will be hit by a 'solar tsunami' this week after two huge explosions on the surface of the sun. The fireworks took place at the weekend and were witnessed by astronomers across the world.

First a flare erupted above a sunspot the size of our planet and soon afterwards a huge explosion of gas, known as a coronal mass ejection, took place in the sun's northern hemisphere. Both events were directed at the earth and the effects of them will be seen in our skies this week.

The two eruptions have sent clouds of electrically charged particles racing towards earth. When the clouds hit, sometime this week, they are expected to spark spectacular displays in the skies around the north and south poles and could even knock out satellites - although this is unlikely.

The coronal mass ejection was the larger of the explosions but is thought to have been triggered by the solar flare.

Dr Lucie Green, of the Mullard Space Science Laboratory in Surrey, who watched events on the sun unfold through Japan's orbiting Hinode telescope, told the Daily Telegraph: "These eruptions occur when immense magnetic structures in the solar atmosphere lose their stability and can no longer be held down by the sun's huge gravitational pull. Just like a coiled spring suddenly being released, they erupt into space."

She added: "It looks like the first eruption was so large that it changed the magnetic fields throughout half the sun's visible atmosphere and provided the right conditions for the second eruption. Both eruptions could be Earth-directed but may be travelling at different speeds.

"This means we have a very good chance of seeing major and prolonged effects, such as the northern lights at low latitudes."

The explosions could be a taste of things to come as astronomers say the sun is awakening from a period of inactivity. Really large events on the surface of the sun could cause magnetic 'space storms' that are strong enough to knock out power and communications systems on earth.

And although the explosions at the weekend are not that dangerous they could still have enough power to take out a satellite - a gust of solar particles is thought to have been responsible for wrecking Intelsat's Galaxy 15 satellite in April.

Source: http://www.thefirstpost.co.uk/66715,news-comment,news-politics,earth-braced-for-solar-tsunami-after-eruptions-on-the-sun-space-satellites-northern-lights

Scientists say the earth could be hit Tuesday by a solar tsunami after two recent massive eruptions on the sun. Solar tsunamis were discovered in 1997 by the Solar and Heliospheric Observatory (SOHO). If forecasters are correct, the solar cycle will peak during the years around 2013, which while it probably won't be the biggest peak on record, human society has never been more vulnerable, says scientists. The basics of daily life - from communications to weather forecasting to financial services - depend on satellites and high-tech electronics. A 2008 report by the National Academy of Sciences warned that a century-class solar storm could cause billions in economic damage.

NASA astronomers reported last week seeing a giant sunspot the size of earth, which in turn was linked to a larger eruption on the Sun's surface. That follows on news in March that after the most profound lull in solar activity for nearly a century, the Sun is finally coming back to life.

Various media reports claim that a large solar eruption could destroy satellites and wreck power and communications grids. Indeed, in mid-July NASA scientists warned that solar storms could cause international havoc by possibly causing widespread power blackouts and affect communication signals.

"The problem is solar storms - figuring out how to predict them and stay safe from their effects," said ILWS Chairperson Lika Guhathakurta of NASA headquarters. "We need to make progress on this before the next solar maximum arrives around 2013."

The Sun sweeps through a cycle of activity that lasts approximately 11 years, notes the ESA webiste, "but until December last year, the Sun had seemed reluctant to start up again. In mid-January, an even larger sunspot group emerged and, most recently, several big, active areas have been crossing the face of the Sun. Yet it is premature to believe that the Sun is ramping up for another energetic cycle of activity."

Predicting solar activity is a complicated problem, akin in some ways to terrestrial weather forecasting but multiplied in difficulty by the thorny physics of solar plasma and magnetism. Predicting the sun is only half the problem, though; the other half is Earth. How our planet's magnetic field and atmosphere respond to any given solar storm is a magnetohydrodynamical riddle that top scientists struggle to understand even with the aid of Earth's most powerful supercomputers. For these reasons, it is often said that space weather forecasting lags 50 years behind its terrestrial counterpart.

Source: http://www.eurasiareview.com/201008036354/solar-tsunami-could-hit-tuesday-may-wreak-havoc-with-satellites.html?utm_source=feedburner&utm_medium=twitter&utm_campaign=Feed%3A+eurasiareview%2FVsnE+(Eurasia+Review)

What is Solar Tsunami?

2010-08-03T15:51:00.000-07:00

Washington, Aug 3, 2010: The Earth could be hit by a solar tsunami anytime, as an unusually complex magnetic eruption on the Sun has flung a large cloud of electrically charged particles towards earth, scientists have warned.

The explosion, called a coronal mass ejection, was aimed directly towards Earth, which then sent a "solar tsunami" racing 93 million miles across space, the New Scientist reported.

Astronomers from all over the world witnessed the huge flare above a giant sunspot the size of the Earth, which they linked to an even larger eruption across the surface of Sun.

Experts said the wave of supercharged gas will likely reach the Earth on Tuesday, Aug 3, when it will buffet the natural magnetic shield protecting Earth.

Several satellites, including Nasa's new Solar Dynamics Observatory, recorded on Sunday, Aug 1, a small solar flare erupting above sunspot 1092, the size of the Earth.

The satellites also recorded a large filament of cool gas stretching across the Sun's northern hemisphere also exploded into space.

"This eruption is directed right at us," said Leon Golub, of the Harvard-Smithsonian Centre for Astrophysics.

However, a really big solar eruption could even shut down global communication grids and destroy satellites also

Source: http://news.oneindia.in/2010/08/03/solar-tsunami-from-sun-may-hit-earth.html

A Moreton wave is the chromospheric signature of a large-scale solar coronal shock wave. Described as a kind of solar'tsunami',^[1] they are generated by solar flares. They are named for American astronomer Gail Moreton, an observer at the Lockheed Solar Observatory in Burbank who spotted them in 1959. ^[2]^[3]^[4]^[5] He discovered them in time-lapse photography of the chromosphere in the light of the Balmer alpha transition.

There were few follow-up studies for decades. Then the 1995 launch of the Solar and Heliospheric Observatory led to observation of coronal waves, which cause Moreton waves. Moreton waves were a research topic again. (SOHO's EITinstrument discovered another, different wave type called 'EIT waves'.)^[6] The reality of Moreton waves (aka fast-modeMHD waves) has also been confirmed by the two STEREO spacecraft. They observed a 100,000-km high wave of hot plasma and magnetism, moving at at 250 km/second, in conjunction with a big coronal mass ejection in February 2009.^[7]^[8]

Moreton waves propagate at a speed of 500-1500 km/s, and occur where a coronal magnetohydrodynamic fast-mode weak shock wave intersects the chromosphere according to a well-known theory of Yutaka Uchida that links them to radio type II bursts. Moreton waves can be observed primarily in the Hα band.^[9]

^{Source: http://en.wikipedia.org/wiki/Moreton_wave}

3-D Solar Tsunami Video Shows the Extreme Waves Are Real

A 60,000-mile-high wave of super-hot plasma blazing across the sun’s surface at 560,000 mph? Yep.
“Now we know. Solar tsunamis are real,” said John Gurman of the Solar Physics Lab at the Goddard Space Flight Center, in a press release Tuesday.
NASA’s Solar Terrestrial Relations Observatory has confirmed that the crazy circular bursts on the surface of the sun, rising higher than the Earth is wide, aren’t just optical illusions.
STEREO consists of two spacecraft pointing at the sun, one ahead of Earth in its orbit and one behind, that acquire stereoscopic images of the sun to give a sort of three-dimensional view, similar to the way our two eyes do.
Though these solar tsunamis, technically known as fast-mode magnetohydrodynamical waves, were first seen by the SOHO mission more than a decade ago, the single spacecraft couldn’t determine if the wave was real or the shadow of a coronal mass ejection. But in February the STEREO twins were perfectly poised to catch the eruption of a sunspot that spawned a wave, seen in the movie above.
“It was definitely a wave,” George Mason University scientist Spiros Patsourakos, lead author of a paper on the solar tsunamis in August in The Astrophysical Research Journal Letters, said in a press release. “Not a wave of water,” he adds, “but a giant wave of hot plasma and magnetism.”

The spacecraft have also spotted waves crashing into other solar structures.
“We’ve seen the waves reflected by coronal holes. And there is a wonderful movie (at right) of a solar prominence oscillating after it gets hit by a wave (near the top of the image),” co-author Angelos Vourdilas of the Naval Research Lab in Washington, D.C., said in a press release. “We call it a dancing prominence.”
Watching the waves interact with other things can reveal new information about the sun’s atmosphere, and help forecast when a coronal mass ejection or radiation storm will impact Earth.
Movies: NASA
NASA press release
Citation: “‘Extreme Ultraviolet Waves’ are Waves: First Quadrature Observations of an Extreme Ultraviolet Wave from STEREO.” by Spiros Patsourakos and Angelos Vourlidas, Astrophysical Research Journal Letters, vol. 700, August 1, 2009.

Source: By Betsy Mason http://www.wired.com/wiredscience/2009/11/solar-tsunami/