| Jingjinbo region is the country's political, economic and cultural center as well as the core of metropolitan Jingjinbo region, but the atmosphere in the region growing regional significant environmental pollution problems, become the world's most serious air pollution in the world. Jingjinbo region of complex terrain, Atmospheric Environment by mountain terrain and the effects of westerly winds, explore the causes of regional air pollution and the law has become urgent needs. In this study, mesoscale meteorological model, Eulerian model and air trajectory model simulation of the regional meteorological field and air pollutant transport market, combined with the key cities in 2008 Air Pollution Index (API) information to verify the results of the simulation analysis. To explore the formation of regional pollution and the elimination of the mechanism, the main conclusion of the study are as follows:(1)On behalf of the city in 2008 of 1,4,7,10 month analysis showed that the API index: Jingjinbo region to show the process of urban pollution better regional pollution process consistency and synchronization, the urban pollution process has shown the characteristics of the sequence.(2)Seasonal variation of atmospheric environmental quality characteristics significantly: the air quality at all levels in different seasons occur in different frequency; different seasons, the changes in urban pollution ranking reflects the seasonal wind field under the direction of the impact of urban air quality. In 2008 on behalf of four months, Beijing, Jinan, Shijiazhuang, the worst air quality in spring and autumn API index cities larger in summer the most stable API index.(3) Jingjinbo region in the MM5 localization parameters, in the selection of four of convective parameterization scheme, Grell simulation program and measured the effect of sounding data in the mid-point value to achieve the best contrast to the effect, but also Jingjinbo region simulated meteorological field characteristics and typical weather characteristics of pollution in the process. (4) study areas of meteorological field simulation showed that the study area has been the typical characteristics of wind transmission. Height near the ground in winter to the north-west flow mainly through the Beijing-Tianjin Bohai. Air transport mainly from the western inland region, the atmospheric transmission channel from the northwest to the southeast; spring to study the prevalence of the region southwest of the northwest wind and wind, there is an obvious area of Beijing-Tianjin Bohai Sea in a south-easterly to the northwest of the transport flow, the lower region more chaotic flow; summer, the study area mainly southerly airstream covered the Beijing-Tianjin Bohai Sea for the inland areas large wind direction, low wind speed greater ability to enhance the proliferation of delivery, less pollution; fall, becoming the northwest wind dominated flow, the transport of pollutants also change the path, leading to seasonal wind field and urban location and API index showed good correlation.(5)On behalf of the month based on the trajectory analysis, by the foreign source of atmospheric pollutants on the Jingjinbo Region, the laws of transportation. Jingjinbo region transport of pollutants from outside the East Asian monsoon is mainly affected by the impact of transportation on the occasion of significant change. A long-distance inter-regional transportation, the Jingjinbo Region a short distance transmission account for a large proportion of the weather through the typical process of pollution was found, close-up of regional transport more serious urban air pollution.(6) By representatives of the city prior to the trajectory calculation, the Jingjinbo Region has been the external pollutants and the impact of the mesoscale transport situation. Different seasons, differences in the distribution of airflow trajectory Obviously, the impact of scope. The activities of the East Asian monsoon region of Jingjinbo-scale transport of pollutants has a very significant impact.(7)Through the course of a typical weather pollution analysis, show that: the existence of pollution near the ground prior to the occurrence of the phenomenon of the wind speed decreases, the existence of pollution when the wind speed increased to eliminate the phenomenon; trajectory simulation shows that the cities of Jingjinbo Region in the lower atmospheric boundary layer regional pollution transport phenomena, the main pollutants for the high-altitude wind direction under the pressure to the next area weather and pollution in the city constitute a serious air pollution; heavily polluting pollutants weather is part of the regional transportation reasons, strong sinking air pollution objects can not remain in the region the rapid spread of the region, coupled with wind speed less pollution occurred, giving rise to serious pollution of the region, with the downward movement of air currents, resulting in the lower reaches of the city appeared one by one the characteristics of high-pollution weather. |
