灰霾天是PM2.5引起的吗？
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- 发布日期：2017-06-23 11:07:53
尽管肉眼看不见空气中的颗粒物，可是颗粒物却能下降空气的能见度，使蓝天不见，天空成为灰蒙蒙的一片，这种气候即是灰霾天。依据《2010年灰霾试点监测陈述》，在灰霾天，PM2.5的浓度显着比平时高，PM2.5的浓度越高，能见度就越低。
Although the invisible particles in the air, but the particles can decrease the air visibility, the sky does not see, the sky has become a gray, the climate is haze days. According to the "2010 pilot monitoring report" in the haze, haze days, the concentration of PM2.5 was significantly higher than usual, the higher the concentration of PM2.5, the lower the visibility.
尽管空气中不一样巨细的颗粒物均能下降能见度，不过比较于粗颗粒物，更为细微的PM2.5下降能见度的才能更强。能见度的下降其本质上是可见光的传达受到阻止。当颗粒物的直径和可见光的波长接近的时分，颗粒对光的散射消光才能最强。可见光的波长在0.4-0.7微米之间，而粒径在这个尺度附近的颗粒物恰是PM2.5的首要组成部分。理论核算的数据也明白地表明这一点：粗颗粒的消光系数约为0.6平方米/克，而PM2.5的消光系数则要大得多，在1.25-10平方米/克之间，其中PM2.5的首要成分硫酸铵、硝酸铵和有机颗粒物的消光系数都在3左右，是粗颗粒的5倍。所以，PM2.5是灰霾天能见度下降的首要原因。
Although particles of different sizes in the atmosphere can reduce visibility, the ability to spot visibility is stronger than that of coarse particles, with more subtle PM2.5 drops. The drop in visibility is essentially the transmission of visible light. When the diameter of the particles is close to the wavelength of visible light, the scattering and extinction of particles are strongest. The wavelength of visible light is between 0.4-0.7 microns, and the particles near the scale are the major components of PM2.5. The theory of accounting data is also clear that this point: the extinction coefficient of coarse particles is about 0.6 m2 / g, and the extinction coefficient of PM2.5 is much greater, in between 1.25-10 square meters / g, the extinction coefficient of PM2.5 primary components of ammonium sulfate, ammonium nitrate and organic particles in 3 about 5 times of coarse particles. So, PM2.5 is the primary cause of haze days reduced visibility.
值得一提的是，灰霾天是颗粒物污染致使的，而雾天则是天然的气候现象，和人为污染没有必然联系。两者的首要区别在于空气湿度，通常在湿度大于90%时称之为雾，而湿度小于80%时称之为霾，湿度在80-90%之间则为雾霾的混合体。
It is worth mentioning that the haze days is particulate matter pollution causes, and fog days is natural climate phenomenon, and not necessarily related to anthropogenic pollution. The first difference between the two is air humidity, usually in the humidity is greater than 90% when called fog, and humidity less than 80% is called haze, humidity between 80-90% for fog and haze mixture.
