Medieval accounts of eclipses shine light on massive volcanic eruptions

中世紀關(guān)于月食的記載揭示了大規(guī)模的火山爆發(fā)

Descriptions of lunar eclipses by monks and other scholars help scientists to pinpoint effects of ancient eruptions.

修道士和其他學(xué)者對月食的描述有助于科學(xué)家確定古代火山爆發(fā)的影響。

Jeff Tollefson（作者）

The great Japanese poet Fujiwara no Teika wrote in his diary of an unusually long and dark lunar eclipse in December 1229, observing that it was as if the Moon had entirely “disappeared”. Now climatologists have used Teika’s account and dozens of other lunar observations made by medieval scholars, clerics and monks to help pin down the timing and impact of?volcanic eruptions?from 1100 to 1300.

日本偉大的詩人藤原定家在1229年12月的一次異常漫長而黑暗的月食日記中寫道，月亮似乎完全“消失”了。現(xiàn)在，氣候?qū)W家利用藤原定家的描述和中世紀學(xué)者、神職人員和修道士進行的數(shù)十次其他月球觀測，幫助確定1100年至1300年火山爆發(fā)的時間和影響。

The research, published in?Nature?on 5 April, corroborates data extracted from?ice cores?and could help scientists to understand the run-up to the cold period known as the Little Ice Age, as well as the effects of a?controversial technique proposed for manipulating the climate.

這項研究于4月5日發(fā)表在《自然》雜志上，證實了從冰芯中提取的數(shù)據(jù)，并有助于科學(xué)家了解被稱為小冰河期的寒冷時期的前期，以及一種有爭議的操縱氣候技術(shù)的影響。【這里指太陽能輻射管理技術(shù)（SDR）】

“If we really want to understand how past volcanic eruptions have impacted climate and societies, I think we need to combine historical archives, where they are available, with ice cores and tree rings,” says Sébastien Guillet, a palaeoclimatologist at the University of Geneva, Switzerland, and a co-author of the study. “None of these methods can work alone.”

“如果我們真的想要了解曾經(jīng)的火山爆發(fā)是怎樣影響氣候和社會的，我認為我們需要將能找到的歷史檔案和冰芯與年輪結(jié)合起來，” 瑞士日內(nèi)瓦大學(xué)的古氣候?qū)W家、該研究的合著者Sébastien Guillet說?！斑@些方法中沒有一個能夠單獨奏效?！?/span>

Dark Moon rising

晦月升起

The authors identified nearly 400 accounts documenting a total of 119 lunar eclipses. Of those, 37 included information about Moon colouration and darkness; scientists can use both traits to determine whether and to what extent a volcanic haze was present at the time.

作者找到了近400個文獻記錄，總共119次月食。其中37條包括關(guān)于月球顏色和晦暗的信息；科學(xué)家可以利用這兩個特征來確定當(dāng)時是否存在火山灰以及火山灰的范圍。

The team documented six dark lunar eclipses, which are indicative of massive eruptions that pushed volcanic aerosols high into the stratosphere, which starts roughly 10 kilometres above Earth’s surface. By combining those accounts with model simulations, modern satellite observations and tree-ring data, the team estimated that the eruptions took place 3 to 20 months before the observations were made. The team identified another five reddish eclipses indicative of eruptions that injected aerosols into the layer below the stratosphere; these aerosols would have had a relatively small impact on the climate.

該團隊記錄了六次月食，這表明大規(guī)模爆發(fā)將火山氣溶膠推高到平流層，平流層始于地表上空10km處。通過將這些描述與模型模擬、現(xiàn)代衛(wèi)星監(jiān)測和樹木年輪數(shù)據(jù)相結(jié)合，該團隊估計火山爆發(fā)發(fā)生在觀測前3到20個月。該團隊發(fā)現(xiàn)了另外五次淡紅色的月食，這表明噴發(fā)將氣溶膠釋放到平流層以下的大氣；這些氣溶膠對環(huán)境影響相對較小。

Dust on ice

靜滯的灰塵

The new record aligns with earlier estimates based on dust layers found in ice cores from Antarctica and Greenland. Seeing an independent record confirm the ice-core chronology “is very comforting”, says Elsa Gautier, a glaciologist at the University of Grenoble Alpes, France, who co-authored the analysis of the Antarctic cores.

這一新記錄與之前基于南極洲和格陵蘭島冰芯中發(fā)現(xiàn)的塵埃層的估計一致。法國格勒諾布爾-阿爾卑斯大學(xué)的冰川學(xué)家Elsa Gautier說，看到一份獨立的記錄證實了冰芯年表 “非常令人欣慰”，她是南極冰芯分析的合著者。

The work could also further scientists’ understanding of the climate in 1100–1300, which could be key to understanding the development of the exceptionally cold period that followed, called the Little Ice Age.

這項工作還可以進一步加深科學(xué)家對1100年至1300年氣候的了解，這可能是了解隨后異常寒冷時期（即小冰河時期）發(fā)展的關(guān)鍵。

Knowing more about what happened in the past could also help to clarify the potential impacts of a controversial proposal known as solar geoengineering, in which particles would be injected into the stratosphere to reflect sunlight back into space. Some scientist argue that such efforts could serve as an emergency backstop to cool the planet and avert the worst effects of runaway global warming.

了解更多關(guān)于過去發(fā)生的事件也能夠幫助澄清被稱為太陽能地質(zhì)工程的有爭議提議的潛在影響，在該提議中微粒被釋放到平流層，使陽光反射回宇宙中。一些科學(xué)家表示這樣的成就能夠作為一種應(yīng)急措施，為地球降溫，避免全球變暖的失控對地球造成最壞的影響。

“Volcanic eruptions are our only — albeit imperfect — analogue for how the Earth’s climate might respond to future solar geoengineering,” says Kevin Anchukaitis, a palaeoclimatologist at the University of Arizona in Tucson. Understanding the precise timing of eruptions can help scientists to improve their models, he says, and “better models should lead to a better understanding of the benefits and risks of geoengineering”.

“火山爆發(fā)或許是我們唯一能模擬未來太陽能地質(zhì)工程對地球氣候影響的方式——盡管不夠完美，” 圖森亞利桑那大學(xué)的古氣候?qū)W家Kevin Anchukaitis說。了解火山爆發(fā)的確切時間可以幫助科學(xué)家改進他們的模型，他說，“更精確的模型應(yīng)該能更好地理解地質(zhì)工程的好處和風(fēng)險”。

For Guillet, who spent a decade poring over historical records in his free time before finishing the project during pandemic lockdowns, the study is also a nod to the medieval observers whose accounts historians have long used to document social and political trends. “If they are able to provide such an accurate record about social and political events, why not about natural events?” he says.

Guillet在完成該項目和疫情封鎖之前，曾花了十年的空閑時間仔細研究歷史記錄，對他來說，這項研究也是對中世紀歷史學(xué)家的致敬，他們長期以來一直記錄社會和政治傾向?！叭绻麄兡軌蛱峁┤绱藴?zhǔn)確的社會和政治事件記錄，為什么不提供自然事件呢？”他說。

doi: https://doi.org/10.1038/d41586-023-00939-9

（本文僅用于學(xué)習(xí)英語，并未用于其他用途）

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