衛(wèi)星圖像顯示冠狀病毒對中國污染水平的影響

衛(wèi)星圖像顯示冠狀病毒對中國污染水平的影響

Data from NASA and the European Space Agency (ESA) pollution monitoring satellites show a sustained decrease in nitrogen dioxide (NO2) over China since the beginning of this year. According to NASA, this is “at least partly” related to the economic slowdown that has ensued from the outbreak of coronavirus.

美國國家航空航天局(NASA)和歐洲航天局(ESA)污染監(jiān)測衛(wèi)星的數(shù)據(jù)顯示，自今年年初以來，中國上空二氧化氮(NO2)持續(xù)下降。據(jù)美國國家航空航天局稱，這“至少部分”與冠狀病毒爆發(fā)導(dǎo)致的經(jīng)濟(jì)放緩有關(guān)。

COVID-19, the disease caused by the SARS-CoV-2 virus, has at the time of writing infected almost 90,000 people and claimed the lives of just over 3,000. Most of the victims have been in the Hubei province in China, where the virus originated. Following the outbreak, people have been under movement restrictions across China, which at one point reportedly affected 500 million people. From transportation halting in Wuhan at the end of January, to local businesses shutting, quarantine measures are being carried out across the country to reduce the spread of the virus.

由SARS-CoV-2病毒引起的COVID-19，在撰寫本文時已經(jīng)感染了近9萬人，奪走了3000多人的生命。大多數(shù)受害者來自中國的湖北省，那里是病毒的發(fā)源地。疫情爆發(fā)后，中國各地的人們都受到了行動限制，據(jù)報道，有5億人受到影響。從1月底武漢的交通停運，到當(dāng)?shù)仄髽I(yè)關(guān)閉，全國各地都在采取隔離措施，以減少病毒的傳播。

Katy Pallister

Like these restrictions, NASA scientists noticed the reduction of NO2, a harmful gas emitted by motor vehicles, power plants, and industrial facilities, first became apparent near Wuhan then spread across the country.

就像這些限制一樣，美國宇航局的科學(xué)家們注意到二氧化氮的減少。二氧化氮是機動車、發(fā)電廠和工業(yè)設(shè)施排放的有害氣體。

“This is the first time I have seen such a dramatic drop-off over such a wide area for a specific event,” Fei Liu, an air quality researcher at NASA’s Goddard Space Flight Center, said in a statement.

美國國家航空航天局戈達(dá)德太空飛行中心的空氣質(zhì)量研究員劉飛(音譯)在一份聲明中說:“這是我第一次看到某一特定事件在如此大的范圍內(nèi)發(fā)生如此劇烈的下降。”

From the information collected by the Tropospheric Monitoring Instrument on ESA’s Sentinel-5 satellite, and a related sensor, the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite, NO2 pollution levels across China have been mapped in several periods: from January 1-20, 2020 (before quarantine), Jan 28-Feb 9, 2020 (Chinese New Year celebrations), and February 10-25, 2020 (during the quarantine).

從歐空局的Sentinel-5號衛(wèi)星對流層監(jiān)測儀器和一個有關(guān)傳感器收集的資料中，美國國家航空航天局(NASA)的Aura衛(wèi)星上的臭氧監(jiān)測儀器(OMI)，中國各地的二氧化氮污染水平已經(jīng)被繪制成幾個時間段:從2020年1月1日至20日(檢疫前)，2020年1月28日至2月9日(春節(jié)慶?；顒?，以及2020年2月10日至25日(檢疫期間)。

Although there is usually a decrease in nitrogen dioxide levels during Chinese New Year celebrations, a rise has not followed the event this year, unlike in 2019. Joshua Stevens / NASA/ ESA

Past observations indicate a usual decrease around Lunar New Year celebrations, when many businesses and factories close in China and much of Asia. However, unlike in 2019 the NO2 levels did not rise again afterwards.

過去的觀察顯示，在農(nóng)歷新年前后，中國和亞洲大部分地區(qū)的許多企業(yè)和工廠都會關(guān)閉，這種情況通常會減少。然而，與2019年不同的是，此后二氧化氮含量沒有再次上升。

“There is always this general slowdown around this time of the year,” Barry Lefer, an air quality scientist at NASA, explained. “Our long-term OMI data allows us to see if these amounts are abnormal and why.”

NASA的空氣質(zhì)量科學(xué)家巴里·萊弗解釋說:“每年的這個時候，空氣質(zhì)量都會普遍下降。”“我們的長期OMI數(shù)據(jù)可以讓我們看到這些數(shù)據(jù)是否異常，以及為什么異常。”

Using OMI’s data, researchers compared NO2 levels in 2020 with the average amounts detected at the same time of year from 2005-2019. They found that in eastern and central China the levels were between 10 to 30 percent lower than what is normally observed for this time period.

利用OMI的數(shù)據(jù)，研究人員將2020年的二氧化氮水平與2005-2019年同期的平均水平進(jìn)行了比較。他們發(fā)現(xiàn)，在中國東部和中部地區(qū)，這一水平比正常時期低10%到30%。

This significant decrease may have other contributing factors beyond the coronavirus quarantine and Chinese New Year celebrations. Lefer noted environmental regulations that China has enforced over the past few years. Previous dramatic decreases in NO2 levels have been observed in several countries, for example during the 2008 economic recession. However, this recent reduction has been much more rapid, leading researchers to believe this event is more than a holiday effect or weather-related variation.

除了冠狀病毒檢疫和春節(jié)慶?；顒又猓@種顯著的減少可能還有其他的影響因素。列弗提到了中國在過去幾年里實施的環(huán)境法規(guī)。此前曾有幾個國家觀察到二氧化氮水平大幅下降，例如在2008年經(jīng)濟(jì)衰退期間。然而，最近這種減少的速度要快得多，這使得研究人員相信，這一事件不僅僅是假日效應(yīng)或天氣相關(guān)的變化。

“This year, the reduction rate is more significant than in past years and it has lasted longer,” Liu said. “I am not surprised because many cities nationwide have taken measures to minimize spread of the virus.”

“今年的降幅比往年更大，而且持續(xù)的時間更長，”劉說。“我并不感到驚訝，因為全國許多城市都采取了措施，盡量減少病毒的傳播。”

This has not been the only time that environmental changes have coincided with global outbreaks of disease. A study from 2017, revealed that the 14th century Black Death outbreak occurred at the same time as the air was lead-free; the first and only time this has happened over the last two millennia. The demographic and economic collapse from the pandemic interrupted metal production, which led the researchers to believe this was at least part of the explanation for the environmental differences.

這并不是環(huán)境變化與全球疾病暴發(fā)同時發(fā)生的唯一一次。2017年的一項研究顯示，14世紀(jì)黑死病爆發(fā)的同時，空氣中也不含鉛;這是近兩千年來第一次也是唯一一次。大流行造成的人口和經(jīng)濟(jì)崩潰中斷了金屬生產(chǎn)，這讓研究人員相信，這至少是造成環(huán)境差異的部分原因。