New study challenges long-held assumptions about the structure of the sun’s atmosphere — ScienceDaily

Many coronal loops — ropey strands of plasma that scientists have lengthy thought existed within the Solar’s ambiance — may very well be optical illusions, based on a brand new paper that challenges prevailing assumptions of what we all know, and do not know, concerning the Solar.

The analysis, led by the Nationwide Heart for Atmospheric Analysis (NCAR) and printed in The Astrophysical Journal, relied on a cutting-edge, life like 3D simulation of the photo voltaic corona. The simulation, carried out at NCAR a number of years in the past, allowed the scientists to slice the corona in distinct sections in an effort to isolate particular person coronal loops.

What they discovered is that most of the loops weren’t loops in any respect.

Whereas the analysis staff was capable of pinpoint among the coronal loops they have been on the lookout for, additionally they discovered that in lots of circumstances what seem like loops in photos taken of the Solar may very well be wrinkles of shiny plasma within the photo voltaic ambiance. As sheets of shiny plasma fold over themselves, the folds appear like shiny skinny strains, mimicking the look of distinct and self-contained strands of plasma.

The findings, which the analysis staff is asking the “coronal veil” speculation, have vital implications for our understanding of the Solar, because the presumed coronal loops have been used for many years as a solution to infer details about density, temperature, and different bodily traits of the photo voltaic ambiance.

“I’ve spent my complete profession finding out coronal loops,” mentioned NCAR scientist Anna Malanushenko, who led the examine. “I used to be excited that this simulation would give me the chance to review them in additional element. I by no means anticipated this. After I noticed the outcomes, my thoughts exploded. That is a completely new paradigm of understanding the Solar’s ambiance.”

The analysis was funded by NASA and included collaborators from NCAR’s Excessive Altitude Observatory, Lockheed Martin Photo voltaic and Astrophysics Laboratory, the Southwest Analysis Institute, and NASA Goddard. NCAR is sponsored by the Nationwide Science Basis.

Difficult instinct

What seems to be coronal loops could be seen in photos taken of the Solar in excessive ultraviolet mild. The idea that they exist is a pure one for scientists as a result of it suits our most elementary understanding of magnetism.

Most schoolchildren have sooner or later seen what occurs when iron filings are sprinkled close to a bar magnet. The filings orient themselves alongside magnetic subject strains that loop from one pole of the bar magnet to the opposite. These curving strains unfold out, turning into weaker and fewer dense, the additional they’re from the magnet.

The obvious coronal loops in photos of the Solar look strikingly related, and since there’s a vital magnetic subject within the Solar, the existence of magnetic subject strains that might lure a rope of plasma between them and create loops looks as if an apparent rationalization. And actually, the brand new examine confirms that such loops seemingly exist.

Nonetheless, the coronal loops seen on the Solar have by no means behaved precisely as they need to, based mostly on our understanding of magnets. For instance, scientists would count on the magnetic subject strains on the Solar to unfold aside, simply as within the iron filings experiment, as you progress larger within the corona. If this occurred, the plasma trapped between the sphere strains would additionally unfold out between the boundaries, creating thicker, much less shiny loops. However photos of the Solar don’t present this phenomenon. As a substitute, the loops additional out nonetheless seem skinny and shiny.

The likelihood that these loops are as an alternative wrinkles in a coronal veil helps clarify this and different discrepancies with our expectations of the loops — but it surely additionally asks new questions. For instance, what determines the form and thickness of the folds? And the way most of the obvious loops in photos of the Solar are literally actual strands, and what number of are optical illusions?

“This examine reminds us as scientists that we should all the time query our assumptions and that typically our instinct can work in opposition to us,” Malanushenko mentioned.

Modern mannequin gives new view of the Solar

The invention that coronal loops could also be illusions was made doable due to a particularly detailed simulation of the photo voltaic corona produced by MURaM, a radiative magnetohydrodynamic mannequin that was prolonged to mannequin the photo voltaic corona in an effort led by NCAR.

The simulation was groundbreaking when it was first produced as a result of it was capable of concurrently mannequin what was taking place in a number of areas of the Solar, from the higher a part of the convective zone — about 10,000 kilometers beneath the Solar’s floor — by way of the photo voltaic floor and past, as much as practically 40,000 kilometers into the photo voltaic corona. These different areas of the Solar cowl an enormous vary of bodily circumstances, together with variations in density and stress, and so scientists had not beforehand found out a solution to mathematically characterize these areas in a unified simulation.

Amongst different outcomes, the brand new simulation was capable of seize your complete life cycle of a photo voltaic flare for the primary time, from the construct up of vitality beneath the photo voltaic floor to the emergence of flare on the floor, and at last to the explosive launch of vitality.

The mannequin additionally produced three-d information units that include the construction of the magnetic subject and plasma, which can be utilized to generate “artificial” observations. As a result of the photo voltaic corona is optically skinny — which means it is comparatively simple to see by way of it — constructions within the corona overlap each other in photos of the Solar. This makes it troublesome to inform whether or not a “loop” that’s overlapping different loops is in entrance or behind. It is also troublesome to inform whether or not the loop itself has a compact cross part, like a backyard hose, or resembles a protracted ribbon seen edge on. It is also doable that what seems to be a skinny strand could also be an optical artifact brought on by a fold in a sheet of shiny plasma.

The cubes of information produced by MURaM present scientists the chance to dissect the photo voltaic ambiance and examine the overlapping constructions individually, one thing that isn’t doable with the observatories and devices we at present have.

Whereas the MURaM simulation is among the most life like ever created of the photo voltaic corona, it is nonetheless only a mannequin. Understanding what number of coronal loops are literally optical illusions would require fastidiously designed observational strategies that probe the corona and new information evaluation methods.

“We all know that designing such methods can be extraordinarily difficult, however this examine demonstrates that the best way we at present interpret the observations of the Solar might not be ample for us to actually perceive the physics of our star,” Malanushenko mentioned.

For Afghan refugees, challenges include lack of affordable housing, job-hunting : NPR

Division of Homeland Safety and non-government personnel wave as the ultimate bus with Afghan refugees aboard departs Joint Base McGuire-Dix-Lakehurst in New Jersey on Feb. 19.

Greg L. Davis/AP/DHS

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Greg L. Davis/AP/DHS

Division of Homeland Safety and non-government personnel wave as the ultimate bus with Afghan refugees aboard departs Joint Base McGuire-Dix-Lakehurst in New Jersey on Feb. 19.

Greg L. Davis/AP/DHS

Previously six months, Feraidon Hakimi has had three completely different houses.

After fleeing from his native Afghanistan final August, the 22-year-old arrived at Washington Dulles Worldwide Airport and was moved to the Fort Pickett army base in Blackstone, Va. 4 months later, he moved right into a home in Maryland. However his journey within the U.S. continues to be simply starting.

“Right here, I’m alone. I’ve nobody to help me financially,” Hakimi stated.

The final teams of Afghan refugees who have been dwelling on U.S. army bases departed this month, however refugee businesses say the refugees nonetheless face immense challenges within the subsequent step of resettlement.

On Feb. 19, the Division of Homeland Safety introduced that every one Afghans who have been quickly housed on U.S. army bases have been “resettled” to communities throughout the nation. The final base that was housing Afghans, Joint Base McGuire-Dix-Lakehurst in New Jersey, will stay partially open to welcome incoming Afghan refugees as a part of the DHS’s Operation Allies Welcome.

DHS says roughly 84,600 Afghan nationals, Americans and lawful everlasting residents have arrived within the U.S. as a part of Operation Allies Welcome, which was established after Afghanistan fell to the Taliban in August 2021. Greater than 76,000 Afghan nationals have now gone to communities throughout the nation, DHS says.

“It is a necessary milestone … however I wish to stress the mission is not over but. The onerous work in some ways is the upcoming weeks and months forward,” Krish O’Mara Vignarajah, president and CEO of Lutheran Immigration and Refugee Service, instructed NPR. The nonprofit has helped settle refugees and migrants arriving within the U.S. for greater than 80 years.

Inexpensive housing continues to be a high concern for resettling refugees

Vignarajah says challenges stay forward for each refugees leaving army bases and the resettlement businesses like hers which are working to assist them. For instance, discovering inexpensive housing continues to be a significant problem, particularly in areas that Afghans choose to stay in like California and Northern Virginia.

“It is a sophisticated strategy of looking for acceptable, inexpensive housing,” Vignarajah says, when “fairly priced lodging are scarce to start with.” A scarcity of housing provide is driving up rents throughout the nation.

Laura Thompson Osuri, govt director of the nonprofit Properties Not Borders, stated help from the federal government to assist refugees discover extra everlasting housing has been missing. Properties Not Borders helps refugees and asylum-seekers within the Washington, D.C., space with furnishings and provides of their houses, as nicely serving to them discover jobs.

“The U.S. wished them off the bases as a result of it was too costly to be on the bases, however now they’re all in resorts, rather a lot are nonetheless in resorts, rather a lot usually are not in everlasting housing,” Osuri stated. “Placing them in resorts is much more costly and extra scattered about.”

NPR reached out to DHS concerning the prices of resettlement efforts and was referred to the State Division. The State Division didn’t instantly reply to remark.

Osuri provides that the dearth of inexpensive housing within the Washington space has made it almost “not possible” for refugee households to seek out everlasting housing within the space.

“It is a nightmare,” she stated. “It is so irritating to see.”

Job-hunting can also be a significant stress

For Hakimi in Maryland, housing hasn’t been his largest concern, he says. After leaving the army base in Virginia in December, Hakimi spent two days in a resort and was then moved to extra everlasting housing in Maryland.

“The method of housing was excellent for me,” Hakimi stated. However now, his best problem is making an attempt to get a job.

“My household usually are not right here, so right here I begin from the zero,” he stated. “I’m not complaining. That is simply my scenario.”

In Afghanistan, Hakimi studied journalism and public relations. Now that he is within the U.S., his associates are advising him to alter his profession path, as a result of he’d must be more adept in English to get a job in PR and have extra expertise. He is additionally making an attempt to determine if he ought to return to highschool within the U.S., and the way he’d pay for that diploma.

The resettlement company serving to Hakimi will present a housing stipend for him for 3 months. He is counting the times he has left earlier than he has to start out paying hire and supporting himself.

“I do not know what I ought to do, to be trustworthy,” he stated. “I haven’t got anybody to help me.”

The Russian invasion of Ukraine leaves organizations bracing for extra refugees

Whereas organizations just like the Lutheran Immigration and Refugee Service are nonetheless offering assist to Afghan refugees, they’re already bracing for one more wave of potential refugees from Ukraine.

“The refugee resettlement system is exactly how we shield weak populations, whether or not they’re from Afghanistan or Ukraine,” Vignarajah stated in a press release on Thursday.

“The U.S. and its allies should put together to reply to the very actual risk of a mass exodus of Ukrainian refugees. Defending the displaced can not merely be an afterthought,” she stated.

U.S. officers have predicted that the Russian invasion of Ukraine may produce between 1 million and 5 million refugees.

“It’s About Executing It And Doing It Together” | Remaining Schedule Full Of Challenges

Right here we go!

The second half of the season will get underway on Friday when Utah hosts Dallas in an enormous showdown between two groups battling for playoff positioning. The Jazz enter Friday ranked No. 4 within the Western Convention whereas the Mavericks are No. 5, simply 1.5 video games behind — making the battle between Donovan Mitchell and Luka Doncic much more thrilling.

However that sport is only the start of what is anticipated to be essentially the most difficult stretch of the season for the Jazz.

Over the ultimate 24 video games, Utah will play opponents with a median profitable proportion of .517, which might rank because the fifth hardest schedule to shut out the season.

Eleven video games will probably be performed in opposition to groups at the moment ranked within the top-6 of both convention. When bumping that to the top-10 of every convention — these at the moment within the play-in — that quantity jumps to 17, together with 12 straight from March 14 by way of April 5.

Whereas some might take a look at that schedule and assume Utah might be in for a world of bother over the ultimate two months of the season, the Jazz are a staff prepared for the problem.

It is tough to argue if one other staff within the league has confronted extra adversity from its gamers all through the previous two months than the Jazz.

Though they have been the final staff within the league to have a participant enter well being and security protocols, as soon as they did, Utah started to lose gamers left and proper.

Donovan Mitchell and Rudy Gobert missed prolonged time coping with accidents whereas prized free-agent acquisition Rudy Homosexual received a late begin to the season and has been sidelined with proper knee soreness.

5 of Utah’s high 9 rotation gamers have missed not less than 12 video games this season, together with former all-star Mike Conley, arguably essentially the most essential piece of the Utah puzzle.

It is tough to beat these points, however the Jazz refused to panic in January amidst the wrestle. There was numerous perception within the locker room that when the staff received wholesome, they’d be capable to flip issues round — they usually did, as evidenced by a six-game profitable streak proper earlier than the all-star break.

“That is the mark of a staff that is composed, and also you perceive you have to undergo adversity to get to the highest,” Mitchell mentioned. “It is having enjoyable with the sport, even in our losses. I am unable to say our losses have been enjoyable, however you take a look at the trouble. … The vitality is simply totally different.”

The excellent news is that the Jazz needs to be accountable for their very own future in the event that they wish to keep within the high 4. They face Phoenix twice and have single video games in opposition to the Warriors and Grizzlies, however will tackle the Mavericks thrice.

When rolling and in a rhythm, the Jazz are extraordinarily powerful to beat — they’ve three separate win streaks of six video games or extra, beginning the season 7-1 and 26-9. The offense is tops within the sport and the protection, when energetic and speaking, is able to being among the finest.

However in keeping with head coach Quin Snyder, if Utah needs to take the subsequent step, they have to be higher at closing out video games. When a staff is weak, he needs to see his gamers step on their opponent’s throats and finish it, not get lackadaisical and allow them to again in. It has been a difficulty for the Jazz this season however is one which’s simply fixable.

“There’s a level once we’ve had alternatives to push away and break open a sport,” Snyder mentioned. “That is the purpose the place we have got to acknowledge and really feel the sport and play these possessions with extra focus and extra recognition of that time within the sport and the way pivotal it’s.”

Sadly, if the Jazz are to achieve success closing out video games, the vast majority of them must come on the street. Utah will finish the season with separate 5 and six-game street journeys.

After the house sport in opposition to Dallas, the Jazz will play 5 video games in 9 days, beginning in Phoenix and ending in Dallas. The excellent news is Utah will play Houston, New Orleans, and Oklahoma Metropolis in between, three groups that rank within the backside of the standings within the Western Convention.

Nevertheless, the ultimate huge street journey of the season is as brutal because it will get, starting within the Large Apple and ending in Southern California’s sunny seashores.

Utah will play a back-to-back in opposition to New York and Brooklyn, the latter of which ought to function Ben Simmons and Kevin Durant suiting up for the Nets. Then come video games in opposition to Boston and Charlotte, two groups at the moment within the Jap Convention playoff image. Utah wraps up the journey with a last showdown in opposition to Dallas and a rematch of final season’s playoffs in opposition to the Clippers.

The Jazz are at the moment 15-12 on the street this season however have misplaced their final 5 video games away from Vivint Enviornment. However lastly wholesome, motivated and on the identical web page, anticipate Utah to make a late-season push and enter the postseason as reputable title contenders.

“It is about embracing the wins and the losses, and I consider in our group,” Gobert mentioned. “I actually consider that we will accomplish our objective. … Every part that we have been by way of solely helped us develop and have ready us even for that second when it comes. I am excited for the second a part of the season, and I do know that we will be able to make a push.”