新奇事件簿 科学家称存在冷空气上升的环境

Most of us learn at school that warm air rises and cool air sinks. This has always appeared to be a fundamental principle of science. However, a study from the University of California, Davis found that there are circumstances in which cool air rises. Researchers discovered that in tropical atmospheres, cold air rises because of the lightness of water vapour. Apparently¹, in warmer and more humid climates, water particles become more buoyant and can help cooler air rise. Lead researcher Dr Da Yang said: "Water vapour has a buoyancy effect which helps release the heat of the atmosphere to space and reduce the degree of warming. Without this lightness of water vapour, the climate warming would be even worse."

我们大部分人在学校里学到的都是，暖空气上升，冷空气下沉。这似乎一直是科学基本原理。但加利福尼亚大学戴维斯分校的一项研究发现存在冷空气上升的情况。研究人员发现在热带大气中，由于水蒸气很轻，所以冷空气会上升。显然在更加温暖潮湿的气候中，水颗粒变得更有浮力，可以帮助较冷的空气上升首席研究员Da Yang博士表示：“水蒸气具有一种浮力效应，可以帮助将大气中的热量释放到空中，并降低升温程度。没有了水蒸气的这种轻度，气候变暖会更糟。”

The scientists said humid air is lighter² than dry air at the same temperatures and pressure. This is called the vapour buoyancy effect. It allows cooler air containing water droplets³ to rise, which then forms clouds and thunderstorms. The resulting rain has a cooling effect in tropical areas. Another researcher, Seth Seidel, said more research is needed to find out the effects rising cool air has on climate change, and on its impact on curbing⁴ the effects of global warming. Seth Seidel said: "Now that we understand how the lightness of water regulates tropical climate, we plan to study whether global climate models accurately⁵ represent this effect." The study is published in the journal "Science Advances".

科学家称，在相同的温度和压力下，潮湿的空气比干燥的空气轻。这被称为蒸汽浮力效应。这种效应让含有水滴的较冷空气上升，然后形成云层和雷暴。由此产生的降雨对热带地区有降温作用。另一名研究员Seth Seidel表示，需要进行更多研究，找出上升冷空气对气候变化的影响，以及对遏制全球变暖作用的影响。Seth Seidel说到：“既然我们了解了水的轻度如何调节热带气候，我们计划研究全球气候模型是否能准确地反映这种影响。”该研究发表于《Science Advances》。

1 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

2 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

3 droplets   

n.小滴( droplet的名词复数 )

参考例句：

• Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
• In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反，从人嘴里呼出的烟则包含相当大的水滴，所以呈白色。 来自辞典例句

4 curbing   

n.边石，边石的材料v.限制，克制，抑制( curb的现在分词 )

参考例句：

• Progress has been made in curbing inflation. 在控制通货膨胀方面已取得了进展。
• A range of policies have been introduced aimed at curbing inflation. 为了抑制通货膨胀实施了一系列的政策。

5 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。