经济学人:空气污染:吹走它(2)

 　　Another good candidate would be a government-run plant at Badarpur, less than 50km from the middle of Delhi. 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。

　　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. 据科学与环境中心（德里的一家调查和游说团体）称，巴达普的电厂是该国污染最严重的发电厂之一。
　　Earlier this month the government shut it down for ten days as part of a set of emergency measures intended to curb 1 a particularly intense bout 2 of air pollution. 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。
　　Dr Alamaro has already found some of the decommissioned jet engines he needs to build his first updrafter. 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。
　　Both the Indian and the American air forces have been forthcoming. 印度和美国空军都已经给他提供了帮助。
　　The Indians have offered six retired 3 engines for nothing  印度空军已经无偿提供了6台退役发动机，
　　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. 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。
　　They are asking for just $5,000 per jet to cover the labour needed to prepare the engines, plus shipping 4. 美国空军只索要了每只5000美元的费用，用来支付机器的搬运劳务费和运输费。
　　Some meteorologists are sceptical. 一些气象学家对此持怀疑态度。
　　They suggest that the engines on offer will not have the oomph to push material through Delhi’s inversion 5 layer,  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，
　　especially during daylight hours, when the boundary between warm and cool air sits at an altitude of around a kilometre. 尤其是在白天，热冷空气的边界大概有一公里宽。
　　They also say that Dr Alamaro’s notion of a virtual chimney is too simple. 他们还说Alamaro博士的虚拟烟囱理论太过简单。
　　Turbulence 6 and friction 7 will weaken the exhaust stream as it climbs. 气流波动和摩擦会在气流上升的过程中削弱气流。
　　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,  此外，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。
　　says Alexander Baklanov, a researcher at the World Meteorological Organisation 8, in Geneva. 日内瓦世界气象组织的一名研究员Alexander Baklanov说道，
　　Dr Alamaro, naturally, disagrees—and if he can keep to his timetable it will not be long before it is clear who is right. 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。
　　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. 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。
　　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. 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。
　　This is because the air contracts into a smaller volume at low temperatures, giving warm air above it room to expand downwards 9. 这是因为空气在低温时体积更小，使得其上方的暖空气能向下扩张。
　　That concentrates airborne gunk, but it also brings the inversion layer within closer range of Dr Alamaro’s jets. 如此会使空气污染更聚集，但是也使得逆温层更靠近Alamaro博士的喷气机喷气范围。
　　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. 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。
　　Dr Alamaro’s jets may offer an alternative. Alamaro博士喷气机也许是个选择。