2006年VOA标准英语-Researchers Make First Sunspot Prediction

By David McAlary
Washington
07 March 2006

NCAR scientists Mausumi Dikpati (left), Peter Gilman, and Giuliana de Toma examine results from a new computer model of solar dynamics   
  
Researchers predict that the next sunspot cycle will be much stronger than the last one, potentially causing more intense solar storms that disrupt electrical activity on Earth. The scientists made their forecast based on a new computer model they say will help societies plan for such disturbances¹ far ahead of time.

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As peaceful as the sun appears, it is really a ball of hot, churning gases. Scientists believe that turbulent gas flows below the surface of the sun cause a cycle of magnetic activity that grows and subsides² over 11-year periods. When the sun's magnetic activity is at its peak, sunspots are numerous and solar storms are generally most intense, spewing out billions of tons of electrically charged particles toward Earth that can cause electrical blackouts and the failure of communications networks and satellites.

Scientists at the U.S. National Center for Atmospheric³ Research developed a computer model of the sun that follows its gas flows. They used telescopes to observe the growth, speed and trail of sunspots, areas of the strongest magnetism⁴ that track the gas movement beneath.

Center researcher Mausumi Dikpati says the computer model, combined with data about previous solar cycles, allows the first forecast of when and how strong the next solar cycle will be.

"We predict that the next solar cycle will be 30 to 50 percent stronger than the last cycle," she said. "Our model also predicted that the onset⁵ of the next cycle will be delayed by six to 12 months to late 2007 or early 2008."

Dikpati says her team's solar sunspot model simulated the strength of the past eight solar cycles with more than 98 percent accuracy, giving them a great deal of confidence in it as a forecasting tool.

Scientists have never been able to accurately⁶ predict the timing⁷ or intensity⁸ of maximum solar activity before. NASA sun researcher David Hathaway calls the new work exciting.

"First of all, it is based on sound physical principles, and secondly⁹, it finally answers the 150-year-old question of what causes the 11-year sunspot cycle," added Hathaway.

The U.S. governments' chief solar storm forecaster, Joseph Kunches of the National Oceanic and Atmospheric Administration, says the findings will help his agency better advise operators of satellites, communications networks, and electrical power grids¹⁰ to anticipate the onslaught of charged solar particles that will require them to protect their systems.

"It's going to help us answer some very difficult questions that users of space weather systems ask us all the time," he noted¹¹. "You can think of this sort of like hurricane season forecasting. The kinds of questions posed to hurricane forecasters also come to us in terms of space weather - when is the next cycle going to start, how strong will it be, what are the effects going to be?"

Solar activity is currently at a low level in the 11-year cycle, with the last peak in 2001. David Hathaway of NASA agrees that the next period of high intensity will be significantly stronger. But he disagrees on the timing, suggesting that sunspot activity will pick up late this year or early next rather than late 2007 or early 2008.

"We have found that large cycles usually start early, and at this point we are anxiously awaiting the appearance of those first spots from the new cycle," he noted.

Even if Mausumi Dikpati is correct about when the solar cycle intensifies¹², her computer model does not predict specific solar storms linked to that intensity. In fact, huge storms can occur during periods of minimum intensity like we are in now, although the likelihood is less. Atmospheric researcher Richard Behnke of the U.S. National Science Foundation near Washington says the real need is for tools to forecast solar storms hours or even days ahead.

"So what we're working on with these models is individual forecasts of particular storms," said Behnke. "That would be what we're really pressed to look at now."

1 disturbances   

n.骚乱( disturbance的名词复数 )；打扰；困扰；障碍

参考例句：

• The government has set up a commission of inquiry into the disturbances at the prison. 政府成立了一个委员会来调查监狱骚乱事件。
• Extra police were called in to quell the disturbances. 已调集了增援警力来平定骚乱。

2 subsides   

v.（土地）下陷（因在地下采矿）( subside的第三人称单数 )；减弱；下降至较低或正常水平；一下子坐在椅子等上

参考例句：

• Emotion swells and subsides. 情绪忽高忽低。 来自《现代汉英综合大词典》
• His emotion swells and subsides. 他的情绪忽高忽低。 来自《现代英汉综合大词典》

3 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

4 magnetism   

n.磁性，吸引力，磁学

参考例句：

• We know about magnetism by the way magnets act.我们通过磁铁的作用知道磁性是怎么一回事。
• His success showed his magnetism of courage and devotion.他的成功表现了他的胆量和热诚的魅力。

5 onset   

n.进攻，袭击，开始，突然开始

参考例句：

• The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
• Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。

6 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。

7 timing   

n.时间安排，时间选择

参考例句：

• The timing of the meeting is not convenient.会议的时间安排不合适。
• The timing of our statement is very opportune.我们发表声明选择的时机很恰当。

8 intensity   

n.强烈，剧烈；强度；烈度

参考例句：

• I didn't realize the intensity of people's feelings on this issue.我没有意识到这一问题能引起群情激奋。
• The strike is growing in intensity.罢工日益加剧。

9 secondly   

adv.第二，其次

参考例句：

• Secondly,use your own head and present your point of view.第二，动脑筋提出自己的见解。
• Secondly it is necessary to define the applied load.其次，需要确定所作用的载荷。

10 grids   

n.格子( grid的名词复数 )；地图上的坐标方格；（输电线路、天然气管道等的）系统网络；（汽车比赛）赛车起跑线

参考例句：

• Typical framed structures are beams, grids, plane and space frames or trusses. 典型构架结构为梁、格栅、平面的和空间的框架或桁架。 来自辞典例句
• The machines deliver trimmed grids for use or stock. 这种机器铸出修整过的板栅，以供使用或储存。 来自辞典例句

11 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

12 intensifies   

n.（使）增强， （使）加剧( intensify的名词复数 )v.（使）增强， （使）加剧( intensify的第三人称单数 )

参考例句：

• A clear atmosphere intensifies the blue of the sky. 纯净的空气使天空变得更蓝。 来自《简明英汉词典》
• Blowing on fire intensifies the heat. 吹火使热度加强。 来自《简明英汉词典》