Lead: These days East haze serious, is considered a very important reason is the recent focus on rural straw burning . The news came out, many users expressed doubts that this is not the key factor leading to the haze events. In the end is not it, to know about the research.
Analysis: Baidu know friends in a small chest big face support (CAS postdoctoral meteorology)
About "farmers burning straw will seriously pollute the air" debate, a typical answer the question: farmers burning straw diet for a long time, why not previously haze?
1. Who says no previous haze? Or "haze" is the word how come?
For example:
"Yuan Shi":
Yuan-day calendar years (1329) in March, "rain dust, haze," "days of the date faint and difficult to see, the way everyone break out the line."
Yuan six years (1340) the twelfth lunar month, "mostly mist, not seeing the sun for several days, all doors hidden in the haze between the wind", "wind shield haze capital for several days, Dili fear wrath of the gods, sent Rites incense Heaven, pray the gods carminative haze and scattered. "
"Ming Kenso Record":
Chenghua four years (1468) spring, "Migration from spring summer this year, the weather was miserable cold, wind haze shadow", "nearly two days to, Huang Wu blocks out the sun, but not the star day and night."
Chenghua seventeen years (1481) in April, "blustery days, dust haze Bikong."
Chenghua twenty-one years (1485), "at the end of the first month Ding, the capital haze blocks out the sun, since Chen is scattered till noon." "Three days later the haze was underway, five days leave, caused by water transport soothing, Imperial officer warehousing meters emergency. "
Koji years (1497), "the capital last winter without snow constant sultry, spring winds haze." "Xizhimen haze of dust accumulation, difficult to see pedestrians, government troops gates ajar, to cover a haze of dust."
Wanli eleven years (1583), "Celebrate yau, the capital of wind haze leap February Saigon, the capital of wind haze, April Guihai, scholar Zhang Siwei and other statements: 'Wind steep as haze, sand Bitian . ' "" Western Hills trace missing five days, there are hungry people into the city and beg, monasteries good and Shi. "
Kangxi six years (1721), "Today (will try) Chubang, Huang Wu four plugs, sand haze blocks out the sun. So windy, the list will be damaged."
Jiaqing fifteen years (1810), "after the capital into the twelfth lunar month, when the fog rose from the haze, even the night until dawn, Wanping, Daxing has reported." "Qiongdao (now the North Sea) fog haze lock closure, difficult to see the true capacity, Meishan hidden in the haze soil wind rain, the palace were hidden in the house, when to visit. "
Xianfeng six years (1856), "since the winter, less snow and fog, haze soil rain wind when the provisional capital in Changping, Wanping is strong."
2. Some readers have always thought that the ancient wood on air pollution, which is a misunderstanding ah!
Of course, there are ancient air pollution, air pollution is not called the word, but also do not know the causes of pollution.
For example, it can be seen from the recording, the ancient view that pollution is "God's Wrath", governance is "incense Heaven, Qi gods carminative haze."
And we now know that the ancient sources mainly: 1 burning biomass, such as straw, charcoal, trees, etc.; 2 dust Jansa.
Both sources (I hereby tentatively called "classical sources"), the case still stable weather system is not conducive to air flow and pollutant dispersion, then the same will produce fog and haze.
3. Of course, the ancient air pollution, and certainly no modern air pollution, is still within the two sources of atmospheric self-cleaning schedule.
But now it is not the same, the energy consumption (such as automobile exhaust) emissions caused by industrial emissions, and form a new source of pollution (in this tentatively called "modern pollution"), which itself has been a heavy burden on the air, coupled with the "classical sources" overlay, far beyond the capacity of the air self-purification, the degree of air pollution unprecedented. This, everyone in the haze must have been fully understood.
4. Many people think that, even for burning straw haze impact, absolutely super, but also the impact of industrial pollution.
This "feel" comes from a kind of inertia of thinking: the traditional and always felt something natural, then that bad no where to go, and the product of the industrial age, it sounds very extinction!
For haze, even though on average, these factors generally is, but for each specific haze, the dominant factor but it may be different.
There is a haze, is called "Straw haze", such as June 10 this year in Nanjing that haze is caused because of the burning of straw. Air pollution index was as high as 410, is already heavily polluted, and the Nanjing Environmental Protection Agency monitoring shows that the concentration of potassium ions in the air of carbon black and a substantial surge in both the characteristics of pollutants is the burning of straw.
So, to sum up:
1. straw burning will seriously pollute the air, causing haze, which have, in modern there in ancient times.
2. With respect to the overall average, greater harm to modern sources, but specific to a certain haze, straw burning is probably the main reason.
In addition, the former record: haze, rain (y) haze, fog soil. Ancient haze associated more with the wind, dust and blowing sand feels very similar (especially such as dust), it is not static stability seen in most weather conditions, it is not often the case now that the haze alternate. Does this mean that the ancient haze, haze has differences with the modern connotation on?
To note here is that the ancient haze, haze wind, but rain haze. Although we can not determine whether this is the ancient rain haze we are talking about the haze, but on the record point of view, the "Qiongdao (now the North Sea) fog haze lock closure, difficult to see the real capacity," "When the fog rose from the haze, even night until dawn "kind of statements should be quite close to the haze.
Of course, the ancient and modern haze haze certainly not exactly the same - let alone haze, the air of ancient and modern air certainly not the same as the ingredients. But this difference does not change as long as the nature, is acceptable.
The nature of the ancient rain haze in particulate matter, and now we are unable to go back through the test, but can still speculate about, is probably blowing dust and residual biomass combustion two kinds.
Ancient straw combustion, certainly not as modern, after all, is important in ancient straw fuel, not large-scale centralized burned up, estimated to be burning a little every day, and then the self-purification of air. But also the ancient burning things, "biomass" in addition to straw and "trees, charcoal," these combustion residues also cause haze.
So to speak, is hereby when large-scale biomass burning, it will certainly increase the particulate matter floating in the air, the case of static stability with the weather, and then there is sufficient moisture, it will form a haze. The difference is, the ancient burning of biomass may be more like homemade charcoal, straw reluctant burned together. Modern straw fuel is not important, but also deal with trouble, they burned together. But their principles and there is no difference, all biomass combustion increases the air particulate matter.
Of course, modern due to industrial emissions, but also increased the level of particulate matter, it does not mean raw particulate matter incinerated does not exist or is not important.
Ancient haze situation alternately, the ratio is relatively low, probably due to the following:
The first is because the ancient meteorological records itself is not much, but also when there is missing data, by itself is not a complete sample to determine the proportion of less rigorous. Description of the ancients, more emphasis on the phenomenon, perhaps the phenomenon is attributable to a similar class, of course, they do not know the essence of the original. So look for previous literature to substantiate it will be more difficult.
The second is because these records more than in the capital, not in Jiangsu and Zhejiang, Beijing wind haze haze is more than normal.
The third and longer time scales may be related to climate change, temporarily unable to confirm this, but it does not exclude the possibility. For example, in recent years, Beijing has increased precipitation, water vapor transport than before, it will lead to an increase of wind haze haze. Perhaps hundreds of years ago, Beijing is now more than a dry, less haze and more wind haze.
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