CRI英语听力2012年03月合辑（文本）：CHINA-METEOROLOGICAL-TOWER-CONTRIBUTES-TO-MONITOR-PM25.doc

1、Beijing has been overshadowed in thick fog and haze in the past three days. Some experts explain that the main pollutant, PM 2.5 particulates have been playing a leading role in air pollution, a meteorological tower in central Beijing is contributing to monitoring the tiny particles in the city.Wei

2、Tong has more.The tower, built by the Institute of Atmospheric Physics of the Chinese Academy of Sciences is situated by the third ring road in northern Beijing. It is 325 meters in height, the highest of its kind in Asia and the second highest throughout the world.Li Aiguo, manager of the tower sai

3、d it was built to facilitate atmospheric research in Beijing.The tower was built for two purposes. One is to facilitate the research on basic rules and process of the atmospheric boundary level and the other purpose, - also a very important one is to help us conduct research on Beijings air pollutio

4、n.Wang Yuesi, an expert at the institute, the visibility at the top of the tower on clear days is about 10 kilometers but it will be reduced to only 2 to 3 kilometers in the smog.The smoke is rising from the big chimney of the thermal power plant. The smoke is going straight up to the sky, which mea

5、ns the wind force is by and large at zero on the ground today. But it is noteworthy that you can feel easterly wind here on the tower. Thats to say there are pollutants coming from outside the city.Wang added that three PM 2.5 particulate detectors were installed at different heights, at 300 meters,

6、 240 meters and 80 meters above the ground.They are used to tell the differences of PM 2.5 particulates at different heights vertically. Through this method, we can find out whether the pollutants are produced locally or coming from neighboring areas through this segmented monitoring. In fact, we ha

7、ve found that the PM 2.5 particulates come from both sources.Meanwhile, a system composed of three PM 2.5 monitoring vehicles will be setup by the end of this year. The vehicles will monitor the tiny particulates along 30 main streets in downtown Beijing, especially particles between 1.2 and 1.5 meters above ground, peoples nose height.For CRI, I am Wei Tong.