The Sun's Magnetic Field is about to Flip
August 5, 2013: Something big is about to happen on the sun. According to measurements from NASA-supported observatories, the sun's vast magnetic field is about to flip.
"It looks like we're no more than 3 to 4 months away from a complete field reversal," says solar physicist Todd Hoeksema of Stanford University. "This change will have ripple effects throughout the solar system."
The sun's magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun's inner magnetic dynamo re-organizes itself. The coming reversal will mark the midpoint of Solar Cycle 24. Half of 'Solar Max' will be behind us, with half yet to come.
Hoeksema is the director of Stanford's Wilcox Solar Observatory, one of the few observatories in the world that monitor the sun's polar magnetic fields. The poles are a herald of change. Just as Earth scientists watch our planet's polar regions for signs of climate change, solar physicists do the same thing for the sun. Magnetograms at Wilcox have been tracking the sun's polar magnetism since 1976, and they have recorded three grand reversals—with a fourth in the offing.
Solar physicist Phil Scherrer, also at Stanford, describes what happens: "The sun's polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle."
Astronomers at the Wilcox Solar Observatory (WSO) monitor the sun's global magnetic field on a daily basis. WSO home page
A reversal of the sun's magnetic field is, literally, a big event. The domain of the sun's magnetic influence (also known as the "heliosphere") extends billions of kilometers beyond Pluto. Changes to the field's polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space.
When solar physicists talk about solar field reversals, their conversation often centers on the "current sheet." The current sheet is a sprawling surface jutting outward from the sun's equator where the sun's slowly-rotating magnetic field induces an electrical current. The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet.
During field reversals, the current sheet becomes very wavy. Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet.
Cosmic rays are also affected. These are high-energy particles accelerated to nearly light speed by supernova explosions and other violent events in the galaxy. Cosmic rays are a danger to astronauts and space probes, and some researchers say they might affect the cloudiness and climate of Earth. The current sheet acts as a barrier to cosmic rays, deflecting them as they attempt to penetrate the inner solar system. A wavy, crinkly sheet acts as a better shield against these energetic particles from deep space.
An artist's concept of the heliospheric current sheet, which becomes more wavy when the sun's magnetic field flips. More
As the field reversal approaches, data from Wilcox show that the sun's two hemispheres are out of synch.
"The sun's north pole has already changed sign, while the south pole is racing to catch up," says Scherrer. "Soon, however, both poles will be reversed, and the second half of Solar Max will be underway."
When that happens, Hoeksema and Scherrer will share the news with their colleagues and the public.
Stay tuned to Science@NASA for updates.
Credits:
Author:Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit: Science@NASA
More information:
Is Solar Max Double-Peaked? -- ScienceCast video
NASA Official: Ruth Netting
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Last Updated: Aug. 6, 2013
Residents baffled over what caused a giant sinkhole in a Kansas pasture
August 5, 2013 – NEAR GOODLAND, Kan. — A mysterious, massive hole in the earth is attracting visitors to western Kansas. Geologists and engineers are still trying to determine how and why the ground gave way in this particular spot south of Goodland in the middle of someone’s pasture. “Man had nothing to do with this. This is a God thing,” said Larry Townsend, Wallace County Sheriff. “There’s no oil well around here. There are no irrigation wells anywhere near. This is something that just happened.” The sink hole is about 200 feet across and 90 feet deep. Some people have let their curiosity overtake their caution and have hiked down into the cavity, but the sheriff warns that hiking into it is a bad idea because they don’t know what’s under it and if it will further collapse. –Fox 4KC
Volcanoes can “recharge” with new magma just days after an eruption
August 1, 2013 – GEOLOGY - A new paper out today in Nature offers some good news and bad news about volcanic eruptions. First, the bad news. The researchers found that certain kinds of volcanoes can unleash a bunch of lava, then “recharge” with new magma from deep in the Earth within a matter of days or weeks. Previously, scientists believed it would take much longer for this recharging to happen. So one of these volcanoes could actually be simultaneously erupting and recharging its magma chamber with superheated rock from the Earth’s mantle. Columbia University Earth scientists Philipp Ruprech and Terry Plank described the situation as “the highway from hell.” Because really, let’s just call it what it is. The good news is that this information could help us predict volcanic eruptions months in advance. By monitoring small earthquakes deep in the Earth’s crust, where these rapid recharges are happening, seismologists might know when an eruption is coming. Usually, volcanic activity is monitored from the Earth’s surface, where small and large quakes will signal that an eruption might be near — especially if the Earth is bulging over the top of the volcano. Now we know that some volcanoes might prepare for their eruptions deep underground, too. –I09
Volcano Watch: U.S. ranks high with number of active volcanoes
July 29, 2013 – ALASKA – When Mount St. Helens erupted explosively in 1980, most people were unaware that the U.S. ranks as one of the top countries in the world in the number of geologically young, active volcanoes. An updated review of the Nation’s active volcanism from 1980 through the end of 2012, however, shows that 107 eruptions occurred at 32 volcanoes (most of which are located in Alaska), and at least 41 episodes of unrest were observed at 13 volcanoes. So far in 2013, four new eruptions have occurred at volcanoes in Alaska (Cleveland, Pavlof, and Veniaminof) and the Commonwealth of Northern Marianas Islands (Pagan), and two eruptions are continuing in Hawai`i at Kilauea Volcano from Halema`uma`u Crater at the summit and the Pu`u `O`o vent 18 km (12 miles) to the east. Also in 2013, various signs of persistent unrest continue at two of the largest volcanoes in the U.S., Yellowstone and Long Valley calderas in Wyoming and California, respectively. The most explosive and harmful eruption in terms of lives lost and economic effects was that of Mount St. Helens. Large explosive eruptions also occurred at Pagan (1981–1985) and Anatahan (2003) in the Commonwealth of the Northern Marianas Islands, and Spurr (1992), Augustine (1986, 2006), Kasatochi (2008), Okmok (1997, 2008), and Redoubt (1989, 2009) in Alaska. The most voluminous lava-producing eruption since 1980 is the ongoing Kilauea eruption (1983-present), which is not showing signs of winding down.
Eruption warnings and regular information updates in the United States are the responsibility of the U.S. Geological Survey (USGS) through the Volcano Hazards Program(VHP) and its five volcano observatories, along with Federal, State, and University partners. In the past 33 years, the capability of the USGS to issue warnings and updates has increased significantly for several key reasons: the astounding improvements in volcano-monitoring, computer, and information technology; a dramatically increased number of monitoring networks installed on volcanoes with the highest threat in the U.S., especially in Alaska; the experience and expertise gained by scientists in understanding volcanic processes and interpreting the early signs of potential volcanic activity; and the creation of coordinated communication and emergency-response plans for use during eruptions and escalating periods of unrest. This unprecedented capability stems from significant long-term investment by the Federal government to reduce volcanic risk in the nation after the eruption of Mount St. Helens, when funding of volcano monitoring and research increased tenfold. In 2005, the USGS characterized this expanded monitoring and warning capability as the U.S. National Volcano Warning System (NVEWS) and developed a framework for expanding the monitoring effort to include more volcanoes deemed a high threat to the nation but that are not sufficiently well-monitored to ensure detection of unrest and warnings well before any eruption might begin. –Big Island
Health Ministry
Space telescope spots gigantic hole in the solar atmosphere
July 29, 2013 – SPACE – A space telescope aimed at the sun has spotted a gigantic hole in the solar atmosphere — a dark spot that covers nearly a quarter of our closest star, spewing solar material and gas into space. The so-called coronal hole over the sun’s north pole came into view between July 13 and 18 and was observed by the Solar and Heliospheric Observatory, or SOHO. NASA released a video of the sun hole as seen by the SOHO spacecraft, showing the region as a vast dark spot surrounded by solar activity. Coronal holes are darker, cooler regions of the sun’s atmosphere, or corona, containing little solar material. In these gaps, magnetic field lines whip out into the solar wind rather than looping back to the sun’s surface. Coronal holes can affect space weather, as they send solar particles streaming off the sun about three times faster than the slower wind unleashed elsewhere from the sun’s atmosphere, according to a description from NASA. “While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere,” NASA’s Karen Fox at the agency’s Goddard Space Flight Center in Greenbelt, Md., explained in an image description. These holes are not uncommon, but their frequency changes with the solar activity cycle. The sun is currently reaching its 11-year peak in activity, known as the solar maximum. Around the time of this peak, the sun’s poles switch their magnetism. The number of coronal holes typically decreases leading up to the switch. After the reversal, new coronal holes appear near the poles. Then as the sun approaches the solar minimum again, the holes creep closer to the equator, growing in both size and number, according to NASA. -Yahoo
NASA confirms sun’s magnetic field is about to flip
August 6, 2013 – SPACE – Something big is about to happen on the sun. According to measurements from NASA-supported observatories, the sun’s vast magnetic field is about to flip. “It looks like we’re no more than 3 to 4 months away from a complete field reversal,” says solar physicist Todd Hoeksema of Stanford University. “This change will have ripple effects throughout the solar system.” The sun’s magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun’s inner magnetic dynamo re-organizes itself. The coming reversal will mark the midpoint of Solar Cycle 24. Half of ‘Solar Max’ will be behind us, with half yet to come. Hoeksema is the director of Stanford’s Wilcox Solar Observatory, one of the few observatories in the world that monitor the sun’s polar magnetic fields. The poles are a herald of change.
Just as Earth scientists watch our planet’s polar regions for signs of climate change, solar physicists do the same thing for the sun. Magnetograms at Wilcox have been tracking the sun’s polar magnetism since 1976, and they have recorded three grand reversals—with a fourth in the offing. Solar physicist Phil Scherrer, also at Stanford, describes what happens: “The sun’s polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle.” A reversal of the sun’s magnetic field is, literally, a big event. The domain of the sun’s magnetic influence (also known as the “heliosphere”) extends billions of kilometers beyond Pluto. Changes to the field’s polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space. When solar physicists talk about solar field reversals, their conversation often centers on the “current sheet.” The current sheet is a sprawling surface jutting outward from the sun’s equator where the sun’s slowly-rotating magnetic field induces an electrical current. The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet. During field reversals, the current sheet becomes very wavy. Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet. -NASA
contribution Kaos
Wednesday, August 7, 2013
The Sun's Magnetic Field is about to Flip, November or December, Sept. or Oct., or Aug., by the year end.
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