灰霾天是PM2.5引起的嗎？
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- 發(fā)布日期：2017-06-23 11:07:53
盡管肉眼看不見空氣中的顆粒物，可是顆粒物卻能下降空氣的能見度，使藍(lán)天不見，天空成為灰蒙蒙的一片，這種氣候即是灰霾天。依據(jù)《2010年灰霾試點(diǎn)監(jiān)測陳述》，在灰霾天，PM2.5的濃度顯著比平時高，PM2.5的濃度越高，能見度就越低。
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.
盡管空氣中不一樣巨細(xì)的顆粒物均能下降能見度，不過比較于粗顆粒物，更為細(xì)微的PM2.5下降能見度的才能更強(qiáng)。能見度的下降其本質(zhì)上是可見光的傳達(dá)受到阻止。當(dāng)顆粒物的直徑和可見光的波長接近的時分，顆粒對光的散射消光才能最強(qiáng)?？梢姽獾牟ㄩL在0.4-0.7微米之間，而粒徑在這個尺度附近的顆粒物恰是PM2.5的首要組成部分。理論核算的數(shù)據(jù)也明白地表明這一點(diǎn)：粗顆粒的消光系數(shù)約為0.6平方米/克，而PM2.5的消光系數(shù)則要大得多，在1.25-10平方米/克之間，其中PM2.5的首要成分硫酸銨、硝酸銨和有機(jī)顆粒物的消光系數(shù)都在3左右，是粗顆粒的5倍。所以，PM2.5是灰霾天能見度下降的首要原因。
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，灰霾天是顆粒物污染致使的，而霧天則是天然的氣候現(xiàn)象，和人為污染沒有必然聯(lián)系。兩者的首要區(qū)別在于空氣濕度，通常在濕度大于90%時稱之為霧，而濕度小于80%時稱之為霾，濕度在80-90%之間則為霧霾的混合體。
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.
