摘要
为了揭示肇庆市颗粒物重污染过程的发生与发展规律,利用2013—2014年PM_(2.5)监测数据,分析该区域两年间的空气质量整体变化情况以及PM_(2.5)污染过程的季节变化规律,统计两年间所有颗粒物重污染过程,并根据污染过程的天气形势展开分析,运用空气质量数值模型(WRF-Chem)对冬季一次典型重污染过程进行模拟研究。结果表明,肇庆2013—2014年共发生27次PM_(2.5)重污染过程且主要出现在秋冬季,结合气象场的分布特征,总结出四种诱发重污染过程发生的天气形势,分别是高压出海型(48%)、热带低压型(22%)、锋面影响型(19%)及冷高压控制型(11%)。在四种天气形势的影响下,肇庆整体风向以东南风和南风为主,大气处于静稳状态,导致污染物的积累并诱发重污染过程。WRF-Chem模拟结果进一步发现,不利气象条件及本地排放源是造成肇庆冬季重污染过程发生的主要原因。结合四维通量模型对肇庆边界污染物输送情况进行定量分析后发现,肇庆PM_(2.5)以输出为主,其中硝酸盐与氨盐的输出通量较大。此外,模型还揭示了肇庆境内的主要污染物输送通道呈东南-西北走向,外地输入的污染物也通过此通道影响肇庆的空气质量。
In order to investigate the occurrence and development of severe particle pollution process, two-years （2013--2014） of continuous observation data of PM2.5 collected in Zhaoqing, Guangdong province were used and analyzed in this study to explore the seasonal variation of air quality and PM2.5 pollution processes. In addition, all the particle pollution processes, combined with their weather condition during 2013 and 2014, were summarized and analyzed, and the air quality numerical model （WRF-Chem） was applied to simulate and study a typical winter heavy haze event. The result showed that, a total of 27 pollution episodes were found in 2013 and 2014, and extreme pollution episodes mainly occurred in autumn and winter season. By analyzing the characteristics of PM2.5 pollution episodes, four typical weather conditions related to pollution episodes were summarized, including weak-high-pressure type （48%）, tropical-depression type （22%）, front type （19%） and strong-high-pressure type （11%）. The prevailing wind direction was southeast and south under the influence of these weather conditions, and the atmosphere was in a steady state, resulting in the accumulation of pollutants and further leading to the occurrence of pollution episodes. Model results revealed that the adverse meteorological conditions and local emission sources were the key reasons for the occurrence of pollution processes. A four-dimensional flux model was employed to study the regional transport flux of atmospheric pollutants. Negative net flux was found for PM25, indicating that the pollutants in Zhaoqing area were exported to adjacent areas, especially NO3- and NH4＋, which showed a relatively high negative flux. In addition, the transport pathway of pollutants in Zhaoqing mainly ran from southeast to northwest. The nonlocal pollutants tend to be transported through the pathway and further influence the air quality of Zhaoqing area.
出处
《热带气象学报》
CSCD
北大核心
2017年第5期782-792,共11页
Journal of Tropical Meteorology
基金
科技部公益性行业(气象)科研专项(GYHY201406031)
国家杰出青年科学基金项目(41425020)
国家科技部支撑项目(2014BAC21B02)
中山大学高性能计算平台共同资助
关键词
天气分析
PM2.5
四维通量
传输特征
肇庆市
synoptic situation analysis
PM2.5
four-dimensional fluxes model
transportation characteristics
Zhaoqing
