Analysis of Meteorological conditions on a persistent haze process in Yangtze River Delta

The Yangtze River Delta area, which is located on the eastern coast of China, is one of regions with economically developed, densely populated, large pollutant emission. In recent years, Along with faster industrialization and urbanization, in the process of those, a large amount of waste residue, waste water, waste gas and other be put into the atmosphere directly or indirectly. At the same time, most city densely clustered, thus reduce the pollutant buffer which originally existed in urban-rural fringe. And pollution is not easy to diffuse. Then air pollution has become more serious in the region, severe haze weather get more frequent. According to meteorological data, taked Nanjing as an example, in the 63 years spanning from 1961 to 2013, haze days increased from 4.2 days to 194 days, an increase of 6.3%. In which, the 2012 has rised 226 days, which means nearly 62% days are controlled by the haze weather in 2012. Especially in December 2013, extremely severe and persistent haze occurred in the Yangtze River Delta area from the north to the south area. The record-breaking high concentrations of particulate matter(PM2.5) has increased more than 400ug/m3 on hourly average, and haze weather has lasted about a week. It is harm to people's health, serious impact on the normal production and life. To improve the air quality in Yangtze River Delta area, has become one of the key problems to realize sustainable development. In fact haze is formed as the result of all these meteorological conditions. So this paper combined meteorological data (including hourly data of temperature, pressure, wind, relative humidity, precipitation, and visibility, as well as the daily values of solar radiation, weather phenomena by fog, haze, dust and sunshine durations) and weather situation, analyzed the haze weather process in the boundary layer meteorological factors and structure, spatio-temporal distribution of aerosol concentration, explained the mechanism of haze formation and continuous formation. That will help to understand the mechanism and changing law of haze weather in this area. Finally, corresponding views to control the air pollution based on the conclusion has been proposed, and it gave evidences to achieve sustainable.