【经济学人】远离“仙境” | 2016.11.26 | 总第754期

TO LAND at Indira Gandhi Airport is to descend from clear skies to brown ones. Delhi’s air is toxic. According to the World Health Organisation, India’s capital has the most polluted atmosphere of all the world’s big cities. The government is trying to introduce rules that will curb emissions—allowing private cars to be driven only on alternate days, for example, and enforcing better emissions standards for all vehicles. But implementing these ideas, even if that can be done successfully, will change things only slowly. A quick fix would help. And Moshe Alamaro, a researcher at the Massachusetts Institute of Technology, thinks he has one.

飞机在英迪拉甘地机场着陆的过程中，天空会由明朗转为棕黄。德里的空气是有毒的。据世界卫生组织报道，印度首都是全世界空气污染最严重的城市。政府正努力制定控制排放的条例，比如：私家车单双数出行、强制提高所有车辆的排放标准。但即使这些方法都能顺利实施，情况也不会立刻好转。一个速成方法将有所帮助。麻省理工学院的一名研究员Moshe Alamaro提出了一个想法。

• implement ['ɪmplɪm(ə)nt] v.实施

His idea is to take a jet engine, put it next to one of India’s dirty coal-fired power plants, point its exhaust nozzle at the sky and then switch it on. His hope is that the jet’s exhaust will disrupt a meteorological phenomenon known as “inversion”, in which a layer of warm air settles over cooler air, trapping it, and that the rising stream of exhaust will carry off the tiny particles of matter that smog is composed of.

他的想法是在印度肮脏的燃煤发电厂的旁边放置一个喷气发动机，将其排气喷嘴对准天空并开启。他希望喷气机的排气将破坏“逆温层”这一气象现象。逆温层里上层空气温度较高，下层温度较低，致使暖空气将冷空气和携带雾霾微粒的上升排气困在里面。

• meteorological  [,miːtɪərə'lɒdʒɪkəl] adj.气象学的

Inversion exacerbates air pollution in Delhi and in many other cities, from Los Angeles to Tehran. A particularly intense example caused the Great Smog of London in 1952, when four days of air pollution contributed to 12,000 deaths. Dr Alamaro thinks a jet engine could punch through the inversion layer to create a “virtual chimney” which would carry the trapped pollution above it, so that it could be dispersed in the wider atmosphere. He calculates that all the emissions from a gigawatt coal-fired power plant could be lifted away using a single engine with a nozzle speed of 460 metres a second. However, he has not calculated whether a jet engine could disrupt the inversion layer and allow the pollution to escape the city—so he is now going to test that hypothesis.

逆温加剧了德里市和其他从天使港一路到德黑兰这些城市的空气污染。最严重的便是1952伦敦烟雾事件——持续四天的空气污染导致了12000人死亡。Alamaro博士认为，喷射发动机可以穿透逆温层，制造一个“虚拟烟囱”，将逆温层里的污染物带到逆温层之上，这样污染物便可以分散到更广阔的大气层中了。根据他的计算，用一个喷气速度为460米/秒的喷射发动机就可以带走一个千兆瓦燃煤电厂的全部排放量。然而他还没有算出一个喷气发动机是否足以穿透逆温层并把污染物带出城市，所以他现在要验证这一假设。

• exacerbate [ɪg'zæsəbeɪt] v.使加剧

• hypothesis [haɪ'pɒθɪsɪs]  n.假设

Within eight months, Dr Alamaro plans to put one of his updrafters next to a coal-fired power plant and monitor what happens using a fleet of drones. He is in discussions with Tata Group, a conglomerate with an electricity-generating arm, to run it next to one of the firm’s power stations. Another good candidate would be a government-run plant at Badarpur, less than 50km from the middle of Delhi. According to the Centre for Science and the Environment, a research and lobbying group based in the Indian capital, Badarpur is one of the most polluting power plants in the country. Earlier this month the government shut it down for ten days as part of a set of emergency measures intended to curb a particularly intense bout of air pollution.

在接下来的八个月内，Alamaro博士计划将气流上升装置放在燃煤发电厂旁边并用一队无人机进行监控。他正在与塔塔集团（拥有一家发电厂）进行商议，并准备在该公司的一家发电站旁进行实验。另一个较好的选择便是位于巴达普（距德里市中心不到50千米）的官办工厂。据科学与环境中心称，（德里的一家调查和游说团体）巴达普的电厂是该国污染最严重的发电厂之一。本月早些时候，政府为了遏制极端严重的空气污染，实施了一系列紧急措施。其中就包括将巴达普电厂强制关闭十天。

• conglomerate [kən'glɒm(ə)rət] n.企业集团

塔塔集团

Dr Alamaro has already found some of the decommissioned jet engines he needs to build his first updrafter. Both the Indian and the American air forces have been forthcoming. The Indians have offered six retired engines for nothing and the Americans are in the process of approving a further four engines from the Boneyard, an aircraft-storage facility located on Davis-Monthan Air Force Base in Arizona. They are asking for just $5,000 per jet to cover the labour needed to prepare the engines, plus shipping.

Alamaro博士已经找到了用来组建第一个气流上升装置的退役喷气发动机。印度和美国海军都已经给他提供了帮助。印度海军已经无偿提供了6台退役发动机，美国海军准备再从Boneyard（位于亚利桑那州戴维斯 - 芒森空军基地的飞机储存厂）调来四台喷气发动机，目前还在批准中。美国海军只索要了每只5,000美元的费用，包括机器的搬运劳务费和运输费。

Some meteorologists are sceptical. They suggest that the engines on offer will not have the oomph to push material through Delhi’s inversion layer, especially during daylight hours, when the boundary between warm and cool air sits at an altitude of around a kilometre. They also say that Dr Alamaro’s notion of a virtual chimney is too simple. Turbulence and friction will weaken the exhaust stream as it climbs. Moreover, even if the technique does work, using it to attack a citywide inversion layer would require so many jets and so much fuel as to be prohibitively expensive, says Alexander Baklanov, a researcher at the World Meteorological Organisation, in Geneva.

一些气象学家对此持怀疑态度。他们表示这些喷射发动机提供的动力不足以把污染物带出逆温层，尤其是在白天，热冷空气的边界大概有一公里宽。他们还说Alamaro博士的虚拟烟囱理论太过简单。气流波动和摩擦会在气流上升的过程中削弱气流。此外日内瓦世界气象组织的一名研究员Alexander Baklanov称，即便该技术有效，但是想要用发动机穿透一个整个城市的逆温层将需要许多发动机和燃料，费用也会高到天上去。

• Turbulence ['tɜːbjʊl(ə)ns] n.骚乱

• prohibitively [prəu'hibitivli] adv.过高地

Alexander Baklanov

Dr Alamaro, naturally, disagrees—and if he can keep to his timetable it will not be long before it is clear who is right. Even if his ambitions for citywide arrays of virtual chimneys prove too ambitious, they may still work in some of the worst cases of pollution. Andreas Christen, who studies urban meteorology at the University of British Columbia, in Vancouver, notes that the direst episodes of pollution happen when air is cold—at night, for example.This is because the air contracts into a smaller volume at low temperatures, giving warm air above it room to expand downwards. That concentrates airborne gunk, but it also brings the inversion layer within closer range of Dr Alamaro’s jets. As Dr Christen observes, some farmers in rich countries already use helicopters to disrupt inversion layers above their fields and thus protect their crops from frost. Dr Alamaro’s jets may offer an alternative.

当然Alamaro博士不同意此说法——如果他能够按时完成实验，那么不久之后就会清楚谁对谁错了。即使他在全市布置虚拟烟囱阵的野心过大，这一措施在极端污染的情况下还是可以用的。温哥华不列颠哥伦比亚大学研究城市气象学的Andreas Christen指出最严重的污染往往出现在天气寒冷时，例如：晚上。期待您的翻译，您可以将翻译留言到文章底部，第二天会有详细解析哦。据Christen博士观察，一些发达国家的农民已经在用直升机来驱散田地上方逆温层从而保护作物免受霜冻了。

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