在线英语听力室_免费在线英语听力学习网站

The Arctic's Anti-Snowball Snowball Effect

北极的反雪球效应

Last Christmas, Santa Claus must have been loading his sleigh in a t-shirt and shorts. Temperatures at the North Pole crept up toward the freezing point when they should have been minus twenty Fahrenheit¹.

去年圣诞节，圣诞老人一定是穿着T恤和短裤在雪橇上装的礼物。北极的温度本应该是零下二十华氏度，然而它却上升到了冰点。

The heat wave was the latest in a series that have swept over the Arctic in recent winters. Climate change has caused steady warming in the region. But it has also helped supercharge these extreme events, which scientists say are tied to storms that spiral north out of the Atlantic.

此次热浪是近几年冬天一系列横扫北极的热浪中最近的一个。气候变化导致该地区持续升温。但它同时也帮忙控制了一些极端事件的发生，而据科学家称，这些极端事件与从大西洋向北席卷而来风暴紧密相连。

\“These winds actually pick up a lot of heat and moisture.”

“这些风实际上会带来很多热量和水分。”

Vladimir Alexeev, a climate scientist at the University of Alaska Fairbanks.

阿拉斯加费尔班克斯大学的气候科学家弗拉基米尔·阿列克谢耶夫说道。

“And the atmosphere carries all this extra moisture and heat to the central Arctic, which results in [a] warmer and moister atmosphere.”

“大气还会把这些额外的水分和热量带到北极，从而导致当地的大气更温暖更湿润。”

Which then warms the surface.

然后致使地表变暖。

Alexeev says the heat ferried north by these storms helps slow the growth of sea ice in winter—causing it to be about 15 centimeters thinner by the end of the season. And thinner ice may have a harder time surviving the summer.

阿列克谢耶夫说，被这些风暴运送到北部的热量使冬季北极海冰的增长减缓——到该季节结束时，海冰或将薄出15厘米。而较薄的海冰会更加难以熬过夏季。

But while the impact of these storms has grown in recent decades, the storms themselves are not happening more often, Alexeev says.

然而，虽然最近几十年这些风暴的影响有所增加，但是风暴本身则不再经常发生了，阿列克谢耶夫说道。

“An important piece of information is that the frequency of those storms is not changing. What’s changing is the area of open water in those regions.”

“比较重要的一点是：这些风暴发生的频率并没有变化。变化的是这些地区的无冰水面的面积。”

As the Atlantic Ocean has warmed up, the amount of sea ice around Scandinavia and Siberia in winter has decreased. So now, instead of passing over an ice-capped ocean, storms blow over larger areas of open water on their way north. And that gives them a chance to pick up more heat and moisture from the sea that they carry into the Arctic, causing stronger heat waves.

随着大西洋的升温，冬季斯堪的纳维亚和西伯利亚周围的海冰数量已经减少。所以现在，一路向北的风暴途径的不再是被海冰覆盖的大洋，而是更大面积的无冰水面。这给了它们一个从北极的海洋中吸收更多热量和水分的机会，从而产生更强的热浪。

Alexeev presented his results in December at the Fall Meeting of the American Geophysical Union in San Francisco.

阿列克谢耶夫于去年12月在旧金山举行的美国地球物理联合会秋季会议上公布了他的研究成果。

Another study by Kent Moore, an atmospheric² physicist³ at the University of Toronto, came out around the same time as the meeting and also linked the heat waves to storms passing over more and more open water. That research is in the journal Scientific Reports.

会议上还同时出现了多伦多大学的大气物理学家肯特·摩尔的另一项研究。该研究也将热浪与风暴途径的无冰水面越来越多联系起来。这项研究发表在《科学报告》杂志上。

Alexeev says the situation could be an example of what scientists call a positive feedback: warming causes the loss of sea ice, which promotes more warming and even more ice loss. In other words, it’s a snowball effect—or in this case, an anti-snowball effect.

阿列克谢耶夫表示，这种情况可能就是科学家们所称的积极回馈的一个例子：气候变暖导致海冰融化，从而进一步加剧变暖，以及导致更多的海冰融化。换句话说，这是一个雪球效应——或者在这里应该被称为反雪球效应。