VOA标准英语2013--Scientists Develop New Ways to Track Greenhouse Gases

 

Scientists Develop New Ways to Track Greenhouse Gases

With more than 18 million people living, working and driving in Los Angeles, the city often is covered in a hazy¹ layer of smog. Stan Sander, senior research scientist at the U.S. space agency's Jet Propulsion Laboratory near LA, describes this layer of visible air.

“That haze² is caused by the fact that the air is trapped inside a layer that’s a few hundred meters to a thousand meters in altitude above the L.A. basin. So it collects those emissions³ from the cars and other sources and forms that layer,” said Sander.

Affecting global climate

Jet Propulsion Lab scientist Riley Duren said these pollutants⁴ include greenhouse gases, such as carbon dioxide and methane⁵, and they do not just hang over the city.

“So these gases have a small local effect, but the bigger impact is on the climate. We’re all in this together. It takes several weeks or months for these gases to mix, but they end up in the atmosphere and they affect everywhere - not just in the local city,” said Duren.

Los Angeles is part of a complicated experiment called the Megacities Carbon Project. The goal is to monitor greenhouse gases and look for long-term trends to see if environmental policies to lower these pollutants actually will work.

Sixteen highly sensitive monitoring devices are being installed throughout southern California on rooftops and media towers. These instruments work continuously to analyze⁶ what is in the air.  

Innovative⁷ monitoring

Scientists also use what is called “remote sensing” to monitor the air. Instruments placed on airplanes and a satellite look at sunlight bouncing off the surface of the earth. By examining how the air changes the quality of that light, scientists can “see” the fingerprints⁸ of carbon dioxide and methane in the air.  

There is one more remote sensing instrument on top of historic Mt. Wilson northeast of Los Angeles. NASA’S Sander said this remote sensing equipment looks down throughout the L.A. Basin and analyzes⁹ the air.

“What we’re hoping to do here on Mt. Wilson is create a sort of pattern or model for the way other cities might be able to measure their greenhouse gas emissions in a very similar way,” said Sander.

Duren said developed countries are trying to reduce emissions, though developing nations face challenging circumstances. “In the developing world, particularly in South America, Africa and Asia, we’re seeing explosive growth in cities because of the combined effects of urbanization and economic growth.”

He said many of these growing cities are at higher risk for the impact of climate change. 

1 hazy   

adj.有薄雾的，朦胧的；不肯定的，模糊的

参考例句：

• We couldn't see far because it was so hazy.雾气蒙蒙妨碍了我们的视线。
• I have a hazy memory of those early years.对那些早先的岁月我有着朦胧的记忆。

2 haze   

n.霾，烟雾；懵懂，迷糊；vi.(over)变模糊

参考例句：

• I couldn't see her through the haze of smoke.在烟雾弥漫中，我看不见她。
• He often lives in a haze of whisky.他常常是在威士忌的懵懂醉意中度过的。

3 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

4 pollutants   

污染物质（尤指工业废物）( pollutant的名词复数 )

参考例句：

• Pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
• The 1987 Amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条（g）的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法

5 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

6 analyze   

vt.分析，解析 (=analyse)

参考例句：

• We should analyze the cause and effect of this event.我们应该分析这场事变的因果。
• The teacher tried to analyze the cause of our failure.老师设法分析我们失败的原因。

7 innovative   

adj.革新的，新颖的，富有革新精神的

参考例句：

• Discover an innovative way of marketing.发现一个创新的营销方式。
• He was one of the most creative and innovative engineers of his generation.他是他那代人当中最富创造性与革新精神的工程师之一。

8 fingerprints   

n.指纹( fingerprint的名词复数 )v.指纹( fingerprint的第三人称单数 )

参考例句：

• Everyone's fingerprints are unique. 每个人的指纹都是独一无二的。
• They wore gloves so as not to leave any fingerprints behind (them). 他们戴着手套，以免留下指纹。 来自《简明英汉词典》

9 analyzes   

v.分析( analyze的第三人称单数 )；分解；解释；对…进行心理分析

参考例句：

• This approach analyzes management by studying experience usually through cases. 这个学派通常从实例获得经验，用以分析管理。 来自辞典例句
• The econometrician analyzes statistical data. 经济计量学者要分析统计材料。 来自辞典例句