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NASA’s sun-kissing Parker Solar Probe finds source of ‘fast’ solar wind

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NASA’s sun-touching Parker Solar probe has flown close enough to our star to spot the fine details of the solar wind — including its origin, “coronal holes” in the sun’s atmosphere.

Armed with this information, scientists may now be able to better predict solar storms that can supercharge auroras over our planet but can also disrupt communication and power infrastructure and pose a threat to satellites, spacecraft and even astronauts.

The Parker Solar Probe tracked the solar wind — a stream of charged particles flowing continuously from the sun — back to where it is generated, a new study reports. This allowed researchers to see characteristics of the solar wind that are lost as it exits the sun’s outer atmosphere, or corona, and before it reaches Earth as a relatively uniform stream.

Related: Parker Solar Probe: First spacecraft to ‘touch’ the sun

The spacecraft saw that the streams of high-energy particles that make up the solar wind match so-called “supergranulation flows” within coronal holes. This discovery pointed to these regions as the source of the “fast” solar wind, which is seen over the poles of the sun and can reach speeds as great as 1.7 million mph (2.7 million kph), around 1,000 times faster than the top speed of a jet fighter.

Coronal holes are believed to form in areas where magnetic field lines emerge from the sun’s surface but do not loop back there. This causes open field lines that spread to fill the space around the sun.

During quiet periods of our star’s 11-year activity cycle, coronal holes are usually found at the poles of the sun. This means that the solar wind that emerges from coronal holes isn’t usually directed toward Earth. But when the sun becomes more active and its magnetic field “flips,” switching poles, coronal holes become more widespread, and these powerful streams of charged particles can be directed at our planet. That knowledge, and these new results, could aid the prediction of potentially disruptive solar storms, study team members said.

“Winds carry lots of information from the sun to Earth, so understanding the mechanism behind the sun’s wind is important for practical reasons on Earth,” team co-leader and University of Maryland-College Park professor James Drake said in a statement. “That’s going to affect our ability to understand how the sun releases energy and drives geomagnetic storms, which are a threat to our communication networks.”

A sun shower

The coronal holes operate like a showerhead, spraying jets of charged particles from evenly spaced “bright spots” where magnetic fields extend out from the sun’s surface, team members said. This gives rise to funnels that can be around 18,000 miles (29,000 kilometers) wide, seen on Earth as bright “jetlets” within coronal holes.

The team thinks that when magnetic fields with opposite directions pass each other in these funnels, magnetic field lines break and then reconnect. It is this process, called magnetic reconnection, that is responsible for flinging out the charged particles that we see as solar wind.

The scientists determined this because the speed of some of the observed particles is up to 10 times greater than the average for the solar wind — something only possible with a powerful phenomenon like magnetic reconnection. Such speeds aren’t possible for particles simply surfing along on plasma, team members said.

“The photosphere is covered by convection cells, like in a boiling pot of water, and the larger-scale convection flow is called supergranulation,” research co-leader Stuart Bale, a physics professor at the University of California, Berkeley, said in the same statement. (The photosphere is the sun’s surface.)

“Where these supergranulation cells meet and go downward, they drag the magnetic field in their path into this downward kind of funnel,” Bale added. “The magnetic field becomes very intensified there because it’s just jammed. It’s kind of a scoop of the magnetic field going down into a drain.”

Bale added that it is the spatial separation of these little drains or funnels that the team saw when they looked at data gathered as the Parker Solar Probe made its close approaches to the sun.

“The big conclusion is that it’s magnetic reconnection within these funnel structures that’s providing the energy source of the fast solar wind,” Bale said. “It doesn’t just come from everywhere in a coronal hole; it’s substructured within coronal holes to these supergranulation cells. It comes from these little bundles of magnetic energy that are associated with the convection flows. Our results, we think, are strong evidence that it’s reconnection that’s doing that.”

Related: Facts about the sun’s age, size and history

RELATED STORIES:

Getting up close and personal to find the origin of the fast solar wind

Studying the fine detail of the solar wind isn’t possible from Earth because, by the time it has traveled 93 million miles (150 million km) to reach our planet and strike its magnetic field, the stream has become a homogenous flow of magnetic fields and charged particles like protons, electrons and helium nuclei.

The Parker Solar Probe launched on Aug. 12, 2018. As of March 17, 2023, the spacecraft had made 15 close approaches to the sun, coming as close as 3.8 million miles (6.1 million km) and racing past the star at speeds as great as 365,000 mph (587,000 kph). Thus, Parker gets close enough to see solar wind details before they are lost.

“Once you get below that altitude, 25 or 30 solar radii [around 11 million to 13 million miles] or so, there’s a lot less evolution of the solar wind, and it’s more structured  —  you see more of the imprints of what was on the sun,” Bale said.

In 2021, the spacecraft passed within about 5.2 million miles (8.4 million km) of the solar surface and raced through jets of material rather than mere turbulence. The team traced those jets back to bunched-up magnetic fields and supergranulation cells on the photosphere.

What the team wasn’t sure of back then, however, was if those charged particles were being accelerated by the slingshot-like action of magnetic reconnection or if they were surfing on waves of hot plasma from the sun. The high energy status of the particles told the team that the former mechanism was responsible for accelerating the charged particles, which also got a boost from turbulence in the plasma called Alfvén waves.

“Our interpretation is that these jets of reconnection outflow excite Alfvén waves as they propagate out,” Bale said. “That’s an observation that’s well known from Earth’s magnetotail, as well, where you have similar kinds of processes.”

Further data from the Parker Solar Probe, as it comes to within around 4 million miles (6.4 million km) of the sun during future close approaches, could help the team confirm their theory. But this could be complicated by the fact that the sun is about to enter solar maximum  —  a period of chaotic and intense activity.

“There was some consternation at the beginning of the solar probe mission that we’re going to launch this thing right into the quietest, most dull part of the solar cycle,” Bale said. “But I think without that, we would never have understood this. It would have been just too messy. I think we’re lucky that we launched it in the solar minimum.”

The team’s research is detailed in a paper published online today (June 7) in thejournal Nature.

 

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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