Many parts of the world have experienced record-high temperatures in recent days.
最近几天，世界许多地方都经历了创纪录的高温。
But much of the United States is dealing with extremely cold weather, thanks to what is known as a polar vortex.
但由于所谓的极地涡旋，美国大部分地区正面临极端寒冷的天气。
A map showing world temperatures over the last several days had a dark red color in the Arctic, Asia, the Middle East, South America and parts of Africa. The dark red means the temperatures are 7 degrees Celsius warmer than the average from just over 20 years ago.
在过去几天显示全球气温的地图中，北极、亚洲、中东、南美和非洲部分地区呈现出深红色。深红色表示温度比20多年前的平均温度高出7摄氏度。
The United States is one of the only places on the map that is dark blue, meaning very cold.
美国是地图上为数不多的深蓝色地区之一，表示非常寒冷。
In the state of North Dakota, wind chills reached minus 56 degrees Celsius. Last week in the state of Missouri, a professional American football game took place as temperatures dropped to minus 20 degrees Celsius.
在北达科他州，风寒温度降至零下56摄氏度。上周，在密苏里州，当温度降至零下20摄氏度时，进行了一场职业美式足球比赛。
On the other side of the world, the world’s top tennis players are playing in unusually warm weather in Melbourne, Australia. The Australian Open is taking place as the city records temperatures nearly 7 degrees warmer than average.
在世界的另一端，世界顶级网球选手正在澳大利亚墨尔本异常温暖的天气中比赛。澳大利亚公开赛正在举行，该城市的温度比平均温度高出近7摄氏度。
The African nation of Oman is in the northern hemisphere, where it is winter. It recently set a record for the warmest January night at 26.4 Celsius. Parts of the southern hemisphere are experiencing warmer-than-usual weather, too. Argentina set a record for warmest January night at 27.3 degrees Celsius.
非洲国家阿曼位于北半球，在那里是冬季。最近，该国创下了1月最温暖夜晚的纪录，达到摄氏26.4度。南半球的一些地区也经历了比平常更温暖的天气。阿根廷创下了1月最温暖夜晚的记录，为摄氏27.3度。
Climate scientists say these extreme temperatures are due to warming in the Arctic.
气候科学家表示，这些极端温度是由北极地区的升温引起的。
They say warming temperatures in the Arctic affect the weather all around the world. The pattern called a polar vortex is not unusual in the Arctic. However, experts say as temperatures in the north warm, the polar vortex widens and affects Canada and the United States.
他们表示，北极地区的升温影响着全球的天气。被称为极地涡旋的模式在北极并不罕见。然而，专家表示，随着北方温度的上升，极地涡旋扩大，并影响到加拿大和美国。
Jennifer Francis is with the Woodwell Research Center in Massachusetts. She is a leading researcher in the theory of Arctic Amplification, which links the periods of cold weather to climate change.
詹妮弗·弗朗西斯就职于马萨诸塞州的伍德韦尔研究中心。她是北极放大理论的主要研究人员，该理论将寒冷天气时期与气候变化联系起来。
She said, “When the Arctic is off-the-charts warm (like now), we’re more likely to see frigid cold invade places like Texas that are ill-equipped to deal with it,” she said.
她说：“当北极异常温暖（就像现在一样）时，我们更有可能看到严寒侵袭像德克萨斯这样设备不足以应对的地方。”
Francis added, “Rapid Arctic warming is one of the clearest symptoms of human-caused climate change.”
弗朗西斯补充说：“迅速的北极升温是人为气候变化的最明显症状之一。”
Judah Cohen works for Atmospheric Environmental Research, a commercial weather company near Boston, Massachusetts. He compared the polar vortex to an ice skater doing a spin.
朱达·科恩在马萨诸塞州波士顿附近的商业气象公司大气环境研究工作。他将极地涡旋比作冰刀漩涡。
When a skater spins very quickly, the “vortex” winds stay close to the skater. But if the skater slows down, the winds lose their tight circle.
当滑冰者快速旋转时，“涡旋”风会紧贴在滑冰者附近。但如果滑冰者减速，风就会失去紧密的旋转。
“All the cold air then gets released away from the center of the polar vortex,” Cohen said.
科恩说：“然后所有的寒冷空气都会从极地涡旋的中心释放出来。”
When that happens in January, the target of the cold air is the United States. Cohen said the current polar vortex is stronger and longer lasting than usual.
当这种情况发生在一月份时，寒冷空气的目标就是美国。科恩表示，当前的极地涡旋比通常更
加强大且持续时间更长。
Marshall Shepherd is a meteorology professor at the University of Georgia. He said that right now, there is a “complex interaction within our climate system.”
马歇尔·谢泼德是乔治亚大学的气象学教授。他说，现在我们的气候系统中存在着“复杂的相互作用”。
“Winter will always bring us cold weather, but like the warm season, it may be changing [in] ways that we understand and [in] ways that we are still learning about,” Shepherd said.
谢泼德说：“冬天总会给我们带来寒冷的天气，但就像温暖的季节一样，它可能正在以我们理解的方式和我们仍在学习的方式发生变化。”
The weather experts said the extreme cold in the U.S. will change to unusually warm weather in several days. But another polar vortex is expected to hit at the end of January.
气象专家表示，美国的极端寒冷将在几天内变成异常温暖的天气。但预计一月底将再次出现极地涡旋。
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Words in This Story
wind chill –n. a measurement of cold based on the wind speed and temperature outside
off-the-charts –expression. not able to be measured based on expected numbers
frigid –adj. extremely cold
spin –v. to move in circular motion on a central point
meteorology –n. the study of weather and weather patters
interaction –n. the combination of two things when mixed
