Takeaway

With the arrival of autumn and winter, the fog-haze weather occurred frequently in the eastern region of China. Faced with the lingering shadow of fog-haze, many people have such a question from the perspective of climate change: Is the frequent occurrence of fog-haze related to global climate change? In this regard, China Weather Net reporter interviewed the China Meteorological Administration National Climate Center climate monitoring office chief climate expert Zhou Bing.

Wonderful view

Behind today's haze weather phenomenon, a large number of atmospheric aerosol particles emitted by human activities are involved. This is no longer a completely natural phenomenon, gradually evolved into a meteorological disaster phenomenon.

Observations show that under the background of climate change, the average wind speed decreases, the number of calm wind (breeze) days increases, the number of stable weather increases, and the number of rainfall days decreases significantly. "The changes in the above climatic background conditions have a certain impact on the decrease of fog days and the increase of haze days in the eastern part of China, that is, the haze days may last longer and be more likely to occur.

Climate change is the external meteorological condition that affects the increase of haze

Since 2013, fog and haze has been put on the report agenda by many domestic media. It is no longer an unfamiliar noun, and it has become a hot topic widely concerned by the government, enterprises and people. Even though the situation in different parts of our country is different, there is no lack of news about people "being haze" or various analysis on fog-haze.

"Fog-haze are two different weather phenomena, and I should talk about them separately when discussing fog-haze." Said zhou bing has done. Usually in atmospheric observation, fog generally refers to the visibility of less than 1 km, relative humidity close to 100% (saturation) conditions, by water vapor condensation (or condensation) produced by the weather phenomenon. The haze is mainly determined by two meteorological variables. Horizontal visibility is less than 10 km, relative humidity is generally less than 80%, and the changes in visibility caused by atmospheric turbidity and blurred vision are mainly caused by haze.

Since 2013, the causes of fog-haze weather have been a hot topic discussed by people from all walks of life. By comprehensive analysis, it can be classified into two categories: natural meteorological factors and man-made effects.

The occurrence of fog-haze weather is induced by meteorological conditions. "The formation, development, maintenance and dissipation of fog-haze are closely related to meteorological conditions, including wind field, water vapor, atmospheric temperature and precipitation, etc." "The reasons for the increase in the number of haze days mainly include the increase of suspended particulates in the air; The decrease of precipitation days is not conducive to pollutant deposition. The decrease of the average wind speed is not conducive to the diffusion of pollutants. High relative humidity is conducive to the formation and maintenance of haze. It can be seen that the increase of haze days is the result of the joint action of natural meteorological conditions and human influence, and the change of different meteorological conditions and human influence will affect the increase of haze days."

"Behind today's haze weather phenomenon, there are a large number of atmospheric aerosol particles emitted by human activities. This is no longer a completely natural phenomenon, gradually evolved into a meteorological disaster phenomenon. The factors affecting haze can be summarized into two categories. The first is internal factors such as the emission of haze aerosol pollution sources, which are mainly influenced by urbanization and human activities. The second is external natural factors such as meteorological conditions, which also includes climate change in weather and climate conditions." Said zhou bing has done.

Zhou Bing said: "The core problem of the generation and development of haze comes from the external meteorological conditions and the accumulation of internal substances. Meteorological conditions at different time scales, such as different seasons, different years and different years, also have their own variation rules. The composition of the main components of aerosol and photochemical smoke mixtures varies greatly at different spatial and temporal scales. Therefore, it is impractical to talk about haze pollution in isolation from meteorological conditions or the determinateness of meteorological factors in disregard of the material conditions of haze."

The haze problem in the eastern region has become increasingly serious in recent 20 years, which is mainly attributed to the significant increase of atmospheric aerosol emitted by human activities. The haze pollution problem in China is more complex than the smog events in London and photochemical smog events in Los Angeles, and its impact goes beyond the interdisciplinary field and into all aspects of society.

A large number of observational facts and studies show that the current climate system is undergoing changes characterized by warming and leading to changes in all components of the climate system. According to the current scientific cognitive ability and level, it is still impossible to accurately answer the clear relationship between the regional haze phenomenon and global warming. However, the fact observation shows that under the background of climate change, the reduction of the average wind speed in China weakens the effect of wind on the transport of pollutants. Secondly, the number of calm winds (light winds) increases, and the number of calm days increases, making it less easy for pollutants to spread. In addition, the number of rain days in the country has decreased significantly, by 10% in the past 50 years, which leads to the weakening of the wet deposition of aerosols and the weakening of the washing ability of rain to haze.

"The changes in the above climatic background conditions will reduce the fog days and increase the haze days in the eastern regions of our country, that is, the haze days may last longer and be more likely to cause certain effects." Said zhou bing has done.

Since the 21st century, the number of haze days in China has been accelerating

In the context of climate change, global warming and an increase in extreme weather events are important facts. Climatic environment, especially atmospheric environmental quality (AQI), has also undergone important changes. Since 2013, haze seems to have a more serious impact on People's Daily life, and people who "live under haze" begin to become more sensitive and irritable.

Then, what about the situation of fog-haze weather phenomenon in China? "In general, the fog and haze in China basically appear in the eastern part of the country (100°E). However, in recent 50 years, the fog-haze weather in China began to show the trend of haze increasing and decreasing." Said zhou bing has done.

From the perennial haze days distribution, frequent haze in our country in late autumn to winter. Zhou Bing explained: "As long as the external meteorological conditions are in the state of calm wind or breeze, there is no precipitation weather, and at the same time there is a high relative humidity, it is easy to have haze. In addition, if the atmospheric circulation system is relatively stable, the haze process will last for many days, or the phenomenon of haze pollution will occur repeatedly. However, with the increase of pollution sources and exogenous transport, other seasons will often have haze. In recent 13 years, the number of haze days in each month has increased compared with all the year round, and the increase is most obvious in autumn."

The monitoring results of the Climate Change Center of the China Meteorological Administration show that the average annual haze days in the eastern part of China (100°E) showed an increasing trend from 1961 to 2013, with an average increase of 2.9 days per decade. Among them, from the 1960s to the middle of the 1970s, the annual number of haze days is less than the usual year; From the late 1970s to the 1990s, it was close to the number of perennial haze days. Since the 21st century, the number of haze days per year has shown an accelerated growth trend.

China was shocked by the smog in 2013. According to the 2013 Bulletin of China Climate Change Monitoring, the average annual number of haze days in the eastern region of China (100°E) in 2013 was 36 days, 29.2 days more than usual, and the annual number of haze days was the highest since 1961.

"From the distribution of cumulative haze days in five years, the range of smog-affected areas in China has gradually increased since 1981," Zhou said. Especially since 2011, the cumulative number of haze days (from January 1, 2011 to September 30, 2014) in the eastern part of China (100°E), North China and most areas south of China have exceeded 100 days. Eastern Inner Mongolia, Xinjiang, Sichuan Basin and other regions that are actually less affected by haze have also seen a significant increase in the cumulative number of haze days."

At present, there are four relatively serious haze areas in China, which are the Beijing-Tianjin-Hebei region, the Yangtze River Delta, the Pearl River Delta and the Sichuan-Chongqing (Chengdu, Chongqing) area.

Since 2007, the number of haze days in the Pearl River Delta region has gradually decreased. In this regard, Zhou Bing said: "The Pearl River Delta region (after 2000) realized the impact of fog-haze weather earlier, so early to take measures to deal with and control, so the number of haze days after 2007 has gradually decreased. This is a fact that deserves our attention, from which we can see that the haze phenomenon in the same densely populated and economically developed areas can be slowed down under effective man-made management."

"In addition, in recent 50 years, the spatio-temporal change characteristics of fog-haze in China have three other characteristics: fog-haze weather in the east and the west, the proportion of haze increased from southeast to northwest; The persistent haze process increased significantly; The number of smog days in big cities has increased significantly compared to small towns." "He added.

The China Meteorological Administration has been on the move

As a weather phenomenon, fog and haze are important contents of ground meteorological observation in various countries. China Meteorological Administration has always attached great importance to the forecast and early warning of heavy pollution weather such as fog and haze and the meteorological support of air pollution.

China's haze observation/monitoring mission has already started corresponding observation and detection since the 1950s. The 183rd Xiangshan Scientific Conference on Aerosol Research held in May 2002 and the National and Regional Scientific Symposium on the Formation Mechanism of Haze and its impact on Climate in December 2002 are epoch-making and landmark in the field of haze research.

"Before this, the annual average number of haze days in the eastern part of the country was less than eight days, and research on haze weather climatology was relatively weak. However, with the rapid growth of haze days and the worsening of haze meteorological and environmental disasters, important achievements have been made in the study of the long-term climate change characteristics of haze and the study of climate impact." Said zhou bing has done.

In view of fog and haze weather, China Meteorological Administration has established a network monitoring system for conventional fog and haze weather across the country, which mainly includes observation of visibility, relative humidity, fog and haze weather phenomena, etc., which is one of the important contents of basic observation and forecast services of meteorological departments. Also gradually carried out in recent years has important influence on the fog haze of PM2.5 aerosol observation and atmospheric environmental quality monitoring, such as research at the same time set up a satellite remote sensing monitoring fog, haze occurrence and development of the space distribution and technology method, to carry out the fog, in the center of the national and regional haze formation analysis, early warning indicators and numerical prediction model research and application development.

"With the development of observation technology, the physical, chemical and optical properties of aerosols have been gradually increased, and some observations of vertical distribution of aerosols have also been carried out." Zhou Bing added.

In order to better implement meteorological protection for air pollution, the China Meteorological Administration has issued the Implementation Plan for the Action Plan on Air Pollution Prevention and Control by Meteorological Departments, which defines the objectives and tasks of environmental meteorological services in the Beijing-Tianjin-Hebei region, the Yangtze River Delta, the Pearl River Delta and other key regions. We will strengthen the application of meteorological satellites and environmental meteorological observation stations in regional fog and haze monitoring, improve the fog and haze monitoring, forecast and early warning system, carry out medium - and short-term forecasts and early warnings of meteorological conditions for fog, haze and air pollution, and release monitoring and early warning information in a timely manner.

Secondly, the Beijing-Tianjin-Hebei Environmental Weather Forecast and Early Warning Center of the China Meteorological Administration was set up, and the operational system for numerical environmental weather prediction in Beijing region was established, and regional environmental weather forecast and assessment reports were issued. We carried out emergency drills for heavy pollution weather in the region, and established a mechanism for data sharing, information reporting, and joint consultation on regional additional pollution in the Beijing-Tianjin-Hebei region and its neighboring regions, thus initially realizing regional joint prevention and control of heavy pollution weather.

In addition, the China Meteorological Administration Cooperation Framework Agreement of the Ministry of Environmental Protection was signed. Jointly with environmental protection departments, it issued the Early Warning Plan for Heavy Pollution Weather in Beijing, Tianjin, Hebei and its surrounding Areas, and formulated detailed rules for the implementation of heavy pollution weather monitoring and early warning in Beijing, Tianjin, Hebei and its surrounding areas. At the same time, China has carried out an early warning and emergency consultation exercise for heavy pollution weather, and launched a joint pilot work with the Ministry of Health and Family Planning and the Ministry of Transport on the impact of fog and haze weather on health and transport.

On the day of this interview, the China Meteorological Administration set up an innovation team for fog and haze monitoring and forecasting. In the future, the team will focus on the research and development of the national and regional fog and haze numerical forecast system, provide scientific and technological support to realize the linkage forecast and early warning of fog and haze in the national, regional and key cities, promote the accuracy rate of the fog and haze forecast in China, and drive the development of environmental meteorological services in the country, region and province (autonomous region, municipality).

The fog and haze weather has affected people's life and travel and human health. Poor visibility can easily cause traffic accidents and delays on airlines, railways and expressways. When haze weather occurs, the atmosphere near the surface contains a large number of various pollution substances, especially the high concentration of PM2.5, which has great harm to human health, prone to pharyngitis, tracheitis, conjunctivitis and other inflammation; This has led to an increase in the incidence of respiratory diseases such as pneumonia, lung cancer and influenza.

As for measures to tackle smog, Zhou said: "Tackling smog requires both internal and external measures. External refers to the changes in meteorological conditions that affect the generation and development of haze, and this part should focus on adaptation countermeasures. The internal part is to start from the pollution sources of haze, such as emission reduction, low-carbon action, etc." In conclusion, Zhou Bing believes that the key to air pollution control lies in the following four aspects:

First, government guidance, joint prevention and control, and structural adjustment. The government has made clear the positioning of cities, scientifically formulated urban planning and rational population distribution. We will accelerate the adjustment of the energy mix, improve public transport management, strictly limit the number of motor vehicles, and promote clean production across the board. We will establish coordinated action plans among cities to combat haze pollution and reduce emissions, implement joint prevention and control measures, accelerate the transformation of the development model and economic restructuring, and reduce the total amount of harmful condensation nuclei in the atmosphere.

Second, monitoring system integration and scientific action. Haze pollution monitoring needs to break through the boundaries between national and local, industry and industry, and strengthen the top-level design, integrated construction and resource sharing policies of the national interdisciplinary and cross-industry atmospheric environment monitoring system. To scientifically analyze haze pollution and its composition, pay attention to the climate effect of haze aerosol in climate change, formulate phased targets for air pollution prevention and control action plans, and build confidence in scientific action for long-term combat.

Third, strengthen the awareness of environmental protection and implement the demonstration system. We will advance reform of the environmental protection management system, improve laws and regulations related to air pollution control, combine pollution emission control with ecological and environmental improvement, strengthen ecological and environmental protection, and improve and restore the functioning of the climate system. To establish a climate feasibility demonstration system for urban planning and major project construction, so as to seek advantages and avoid disadvantages and rationally use climate resources.

Fourth, science popularization first, low-carbon life, green travel. The influence of human activities on climate change and climate environment has been gradually accepted by society. Developed countries have experienced a long process of pollution problems caused by industrialization and urban traffic and their treatment. Advanced experience and technology are worth learning and reference. People try to reduce energy consumption, resource depletion and carbon emissions in their daily life.conclusion

Air pollution not only comes from industry, automobile exhaust, construction sites and so on, but also from People's Daily life. Smog and haze are having an increasingly significant impact on economic and social development and the public's work and life. Removing smog and haze is not an overnight task, and requires the concerted efforts of the government, enterprises and individuals. Among them, the government should actively carry out various forms of propaganda and education, spread scientific knowledge of the prevention and control of atmospheric pollution, advocate the civilization, green consumption and saving habits, guide the public from oneself, start from the intravenous drip, start from around things, set up in the whole society ", the struggle together "code of conduct, to improve air quality. Of course, the news media should also actively publicize the policies and measures adopted by the state and the results obtained, strengthen the supervision of public opinion, create a good atmosphere for improving the quality of atmospheric environment, and play a role in the protection of atmospheric environment. A benign effect.

(Source: China Weather Network)