雷雨時劃破長空的閃電有一個你不知道的功能，那就是凈化空氣，而且還有助于抗擊全球氣候變暖。新研究發(fā)現(xiàn)，閃電會釋放大量的“化學清洗劑”，幫助大氣自我凈化。

What is the purpose of lightning? That might sound like a deeply philosophical question, but scientists may have shed some more light on the answer with the results of a recently released study.

閃電的功能是什么？聽上去可能像是一個深刻的哲學問題，但是科學家最近發(fā)布的一項研究結果也許能對這一問題的答案帶來一些啟示。

The new study published at the end of April in Science found that lightning may play a bigger role in global climate change than was previously known by the scientific community. "Lightning increases the atmosphere's ability to cleanse itself," the researchers wrote in the study.

這項四月末發(fā)表在《科學》雜志上的新研究發(fā)現(xiàn)，閃電對全球氣候變化的影響力可能比科學界先前所了解的更大。研究人員在報告中寫道：“閃電會提高大氣自我凈化的能力?！?/p>

Many are familiar with the potentially deadly hazards posed by lightning, which is blamed for an average of 43 fatalities in the United States each year, based on data from 1989 to 2018. Although the odds of being struck are quite low -- 1 in 1,222,000 in a given year and 1 in 15,300 in a lifetime -- many in the weather community have long urged people to take proper precautions to stay safe amid storms, which can frequently trigger lightning, even without turning severe.

許多人對閃電潛在的致命危害很熟悉，基于1989年到2018年的數(shù)據(jù)，美國每年平均有43人因閃電而喪生。盡管被閃電擊中的概率相當?shù)?，一年被閃電擊中的概率只有122.2萬分之一，一輩子的概率只有15300分之一，但是長久以來氣象界一直敦促人們在暴雨來臨時采取適當?shù)姆婪洞胧┮员ＷC安全，暴雨經常會引發(fā)閃電，即使不是強暴雨也可能出現(xiàn)閃電。

However, the researchers recently uncovered a surprising and beneficial impact of lightning.

然而，研究人員最近發(fā)現(xiàn)了閃電的一個驚人的有益影響。

The Earth is struck by lightning nearly 20 million times each year, and bolts of lightning can travel as much as 10 to 12 miles from a thunderstorm, instantly heating the air to 50,000 degrees Fahrenheit, according to the National Weather Service.

根據(jù)美國國家氣象局的數(shù)據(jù)，地球上每年發(fā)生的閃電次數(shù)可達近2000萬次，雷雨過程中閃電可行進10到12英里（16到19公里），瞬間讓空氣升溫華氏5萬度。

The study, which included contributions from nine atmospheric researchers across a dozen universities and meteorological agencies, was based on an airborne research flight conducted by a NASA DC-8 storm-chasing plane in 2012. The plane was used to examine the top portion of thunderstorm clouds, which are known as anvils.

這項研究綜合了12所大學和氣象機構的9位氣象研究員的成果。研究基于2012年美國宇航局DC-8風暴追逐機開展的一項空中飛行實驗，實驗中的飛機用于查看雷暴云頂層的砧狀云。

According to Dr. William Brune, a professor of meteorology and atmospheric sciences at Pennsylvania State University and co-author of the study, researchers initially thought there was a problem with the equipment on the plane, which was being used to measure the hydroxyl radicals (OH) in the atmosphere until they realized spikes they observed corresponded with lightning flashes, ABC News reported.

據(jù)ABC新聞網報道，該研究的合著者、賓夕法尼亞州立大學的氣象學和大氣學教授威廉·布龍博士稱，研究人員一開始認為飛機上用來測量大氣中的羥基自由基的設備有問題，直到他們觀察到羥基自由基水平的飆升和閃電有關。

Hydroxyl radicals, described as a "chemical scavenger" by Science Direct, are important chemical compounds found in the atmosphere due to the reactive nature with other organic molecules.

被Science Direct數(shù)據(jù)庫描述為“化學清洗劑”的羥基自由基是大氣中發(fā)現(xiàn)的重要化合物，可以和其他有機分子發(fā)生反應。

Researchers previously understood that lightning could help to clean the atmosphere, but there was no evidence that it could generate compounds like these radicals.

研究人員先前了解到，閃電可以有助于清潔大氣，但是沒有證據(jù)表明閃電可以產生羥基自由基這樣的化合物。

"No one has seen that much in the atmosphere from natural processes, ever," Brune said.

布龍表示：“從來沒有人見過大氣自然產生這么多羥基自由基?！?/p>

As a result, the study estimates that somewhere between 2% and 16% of the oxidizing, or cleaning that happens naturally in the Earth's atmosphere, is done by lightning.

因此，研究估計，地球大氣中自然發(fā)生的氧化或清潔有2%到16%是由閃電完成的。

Why is this significant? The oxidation process helps to reduce chemicals like carbon monoxide and methane in the atmosphere. These chemicals, known for being greenhouse gases, have been proven to contribute to rising temperatures associated with climate change.

為什么大氣中的氧化很重要？因為氧化過程有助于降低大氣中一氧化碳和甲烷等化學物質含量。經證實，這些被稱為溫室氣體的化學物質導致氣溫升高，而氣溫升高和氣候變化有關。

Researchers say that more studies will need to be conducted to verify the degree to which lightning contributes to the fight against global climate change.

研究人員表示，還需要開展更多研究，才能確定閃電對于抗擊全球氣候變化的貢獻程度。

英文來源：AccuWeather

翻譯&編輯：丹妮