VOA科学技术2024--Sun's Magnetic Field Forms Close to Surface

New research suggests that the sun's magnetic field forms much closer to the surface than scientists had thought. The finding could help predict periods of extreme solar storms like the ones that hit Earth earlier this month.

The magnetic field appears to form 32,000 kilometers under the sun's surface. Earlier estimates suggested the formation began more than 209,000 kilometers below the sun's surface, an international team reported last week.

The sun's strong magnetic energy is the source of solar flares² and bursts of plasma³ known as coronal mass ejections. Plasma is a gas that creates an electromagnetic field. When directed toward Earth, the bursts create colorful displays in the sky. Such displays are also known as auroras. Auroras can also affect power and communications.

Geoffrey Vasil is a professor at the University of Edinburgh's School of Mathematics. He is a lead writer of the new study, which appeared in the publication Nature. Vasil said, "We still don't understand the sun well enough to make accurate predictions" of space weather."

The Italian scientist Galileo was among the first astronomers⁴ to study sunspots. He did so in the early 1600s. Solar flares and coronal mass ejections often occur near sunspots. The dark spots as big as Earth are located near the most intense parts of the sun's changing magnetic field.

Vasil and his team created new models of the interaction between the sun's magnetic field and the flow of plasma. The interaction varies at different latitudes⁶ during an 11-year cycle. The team then entered their calculations into a NASA supercomputer in California. The results suggested a shallow magnetic field. More research is needed to confirm the finding, however.

The new knowledge should improve long-term solar forecasts, permitting scientists to better predict the strength of the sun's future cycles. The sun is nearing its peak level of activity in the current 11-year cycle. This is a reason for the recent solar storms.

Strong solar flares and outbursts of billions of tons of plasma earlier this month created severe solar storms that produced auroras in unexpected places. Earlier this month, the sun released its biggest solar flare¹ in almost 20 years, but it avoided Earth.

Daniel Lecoanet is a professor at Northwestern University in Illinois. He is one of the study's co-writers. He said better understanding of the sun can help make sure that "we are prepared for when the next storm - potentially much more dangerous - hits Earth."

Words in This Story

flare - n. to shine or burn suddenly and briefly⁷

display - n. an arrangement of objects intended to decorate, advertise, entertain, or inform people about something

accurate - adj. free from mistakes or errors

vary - v. to be different or to become different

eruption⁸ - n. to send out rocks, ash, lava⁹, etc., in a sudden explosion

latitude⁵ - n. distance north or south of the equator measured in degrees up to 90 degrees

shallow - adj. having a small distance to the bottom from the surface or highest point

forecast - n. a statement about what you think is going to happen in the future

potential - n. a chance or possibility that something will happen or exist in the future

1 flare   

v.闪耀，闪烁；n.潮红；突发

参考例句：

• The match gave a flare.火柴发出闪光。
• You need not flare up merely because I mentioned your work.你大可不必因为我提到你的工作就动怒。

2 flares   

n.喇叭裤v.（使）闪耀( flare的第三人称单数 )；（使）（船舷）外倾；（使）鼻孔张大；（使）（衣裙、酒杯等）呈喇叭形展开

参考例句：

• The side of a ship flares from the keel to the deck. 船舷从龙骨向甲板外倾。 来自《简明英汉词典》
• He's got a fiery temper and flares up at the slightest provocation. 他是火爆性子，一点就着。 来自《现代汉英综合大词典》

3 plasma   

n.血浆，细胞质，乳清

参考例句：

• Keep some blood plasma back for the serious cases.留一些血浆给重病号。
• The plasma is the liquid portion of blood that is free of cells .血浆是血液的液体部分，不包含各种细胞。

4 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

5 latitude   

n.纬度，行动或言论的自由(范围)，(pl.)地区

参考例句：

• The latitude of the island is 20 degrees south.该岛的纬度是南纬20度。
• The two cities are at approximately the same latitude.这两个城市差不多位于同一纬度上。

6 latitudes   

纬度

参考例句：

• Latitudes are the lines that go from east to west. 纬线是从东到西的线。
• It was the brief Indian Summer of the high latitudes. 这是高纬度地方的那种短暂的晚秋。

7 briefly   

adv.简单地，简短地

参考例句：

• I want to touch briefly on another aspect of the problem.我想简单地谈一下这个问题的另一方面。
• He was kidnapped and briefly detained by a terrorist group.他被一个恐怖组织绑架并短暂拘禁。

8 eruption   

n.火山爆发；（战争等）爆发；（疾病等）发作

参考例句：

• The temple was destroyed in the violent eruption of 1470 BC.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
• The eruption of a volcano is spontaneous.火山的爆发是自发的。

9 lava   

n.熔岩，火山岩

参考例句：

• The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
• His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。