VOA科学技术2024--When Does Air Turbulence Become Dangerous?

If you have flown on an airplane before, you might have experienced turbulence¹. Turbulence is a sudden movement of air. It can move the plane around and force sudden changes in height.

Flying through mild turbulence feels like driving a car over big bumps or holes in the road.

But passengers on a Singapore Airlines flight on Tuesday experienced severe turbulence. Several people were injured and one person, a 73-year-old British man, died. The exact cause of the man's death is still unclear.

While turbulence-related deaths are rare, injuries have increased over the years. Some weather and aviation experts have noted² increasing reports of turbulence. They say climate change may be behind the increase.

What is turbulence?

Turbulence is unstable³ air that moves unpredictably. Most people link it with heavy storms. But the most dangerous kind is clear-air turbulence. This often happens with no warning signs in the sky ahead.

Clear-air turbulence happens most often in or near rivers of air called jet streams. The cause is something called wind shear⁴. That is when two huge air masses near each other move at different speeds. If the difference in speed is big enough, it breaks into circular movements.

Thomas Guinn is an aviation science expert at the Embry-Riddle Aeronautical⁵ University in Daytona Beach, Florida. He said, "When you get strong wind shear near the jet stream, it can cause the air to overflow⁶. And that creates these chaotic⁷ motions in the air."

How common are turbulent-related injuries?

The U.S. National Transportation Safety Board (NTSB) reported that more than one-third of all airline incidents in the U.S. from 2009 to 2018 were related to turbulence. Most of them resulted in one or more serious injuries to passengers, but no damage to the plane.

Between 2009 and 2022, the NTSB said 163 people were injured seriously enough during turbulence events to require hospital treatment for at least two days. Most of those injured were flight attendants. They are especially at risk because they are more likely to be out of their seats during a flight.

Singapore Airlines said its plane dropped about 1,800 meters in about three minutes last Tuesday, after hitting severe turbulence over the Indian Ocean. In addition to the one death, six or seven passengers were severely⁸ injured. Several others suffered less serious injuries.

Larry Cornman is a scientist at the U.S. National Center for Atmospheric⁹ Research. He has studied turbulence for many years. He said, "It's not uncommon¹⁰ to have turbulence encounters that cause minor¹¹ injuries up to, say, a broken bone,... But fatalities¹² are very, very rare - especially for large transport aircraft."

Stuart Fox is with the International Air Transport Association. He said, until Tuesday, it had been 27 years since a passenger died following clear-air turbulence on a major airline.

Can pilots avoid turbulence?

Pilots use several methods to avoid turbulence, including using weather radar¹³ images. Sometimes they can simply see and fly around the storms.

But clear-air turbulence can happen unexpectedly.

Doug Moss¹⁴ is a former airline pilot and safety expert. He said air traffic controllers will warn pilots after another plane runs into clear-air turbulence. Many pilots also look at the upper-level jet streams along their flight path for signs of wind shear. They can plan to move above, below, or around those areas, he added.

Does climate change lead to more turbulence?

Some scientists note that reports of turbulence encounters are on the rise. There are several possible explanations for that. But several researchers have pointed¹⁵ to climate change.

Guinn, of Embry-Riddle Aeronautical University, explained that some experts predict climate change could change the jet stream and increase the wind shear. This would drive up turbulence in the air.

Paul Williams is a professor of atmospheric science at Britain's University of Reading. In a statement Tuesday, he said there was "strong evidence that turbulence is increasing because of climate change."

Williams said his research team recently discovered that severe clear-air turbulence in the North Atlantic has increased by 55 percent since 1979. The team estimated that severe turbulence in the jet streams could double or triple in the coming years under current conditions.

Other experts note that an increase in air travel could be the reason for the increase in turbulence encounters.

How can travelers stay safe?

Turbulence can be hard to predict. But experts note that the first line of defense¹⁶ in the air is keeping seat belts fastened whenever possible.

"Wear your seat belt," Guinn said. "That's just a really quick fix to prevent injury."

Words in This Story

aviation - n. the business and practice of flying airplanes, helicopters...

unstable - adj. having a physical state that can change easily

chaotic - adj. in a state of complete confusion or disorder¹⁷

encounter - n. an occasion when you deal with or experience something

fatality¹⁸ - n. a death that results from a disaster, accident

triple - v. to cause something to become three times as many

fasten - v. to close and attch something

1 turbulence   

n.喧嚣，狂暴，骚乱，湍流

参考例句：

• The turbulence caused the plane to turn over.空气的激流导致飞机翻转。
• The world advances amidst turbulence.世界在动荡中前进。

2 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。

3 unstable   

adj.不稳定的，易变的

参考例句：

• This bookcase is too unstable to hold so many books.这书橱很不结实，装不了这么多书。
• The patient's condition was unstable.那患者的病情不稳定。

4 shear   

n.修剪，剪下的东西，羊的一岁；vt.剪掉，割，剥夺；vi.修剪，切割，剥夺，穿越

参考例句：

• Every spring they shear off the sheep's wool and sell it.每年春天他们都要剪下羊毛去卖。
• In the Hebrides they shear their sheep later than anywhere else.在赫伯里兹，剪羊毛的时间比其他任何地方都要晚。

5 aeronautical   

adj.航空（学）的

参考例句：

• Many of the pilots were to achieve eminence in the aeronautical world. 这些飞行员中很多人将会在航空界声名显赫。 来自辞典例句
• The advent of aircraft brought with it aeronautical engineering. 宇宙飞船的问世导致了航天工程的出现。 来自辞典例句

6 overflow   

v.(使)外溢，(使)溢出；溢出，流出，漫出

参考例句：

• The overflow from the bath ran on to the floor.浴缸里的水溢到了地板上。
• After a long period of rain,the river may overflow its banks.长时间的下雨天后，河水可能溢出岸来。

7 chaotic   

adj.混沌的，一片混乱的，一团糟的

参考例句：

• Things have been getting chaotic in the office recently.最近办公室的情况越来越乱了。
• The traffic in the city was chaotic.这城市的交通糟透了。

8 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

9 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。

10 uncommon   

adj.罕见的，非凡的，不平常的

参考例句：

• Such attitudes were not at all uncommon thirty years ago.这些看法在30年前很常见。
• Phil has uncommon intelligence.菲尔智力超群。

11 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

12 fatalities   

n.恶性事故( fatality的名词复数 )；死亡；致命性；命运

参考例句：

• Several people were injured, but there were no fatalities. 有几个人受伤，但没有人死亡。
• The accident resulted in fatalities. 那宗意外道致多人死亡。 来自《简明英汉词典》

13 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

14 moss   

n.苔，藓，地衣

参考例句：

• Moss grows on a rock.苔藓生在石头上。
• He was found asleep on a pillow of leaves and moss.有人看见他枕着树叶和苔藓睡着了。

15 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

16 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

17 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

18 fatality   

n.不幸，灾祸，天命

参考例句：

• She struggle against fatality in vain.她徒然奋斗反抗宿命。
• He began to have a growing sense of fatality.他开始有一种越来越强烈的宿命感。