一次典型沙尘过程对我国热带地区空气质量影响分析

Analysis of the impact of a typical dust storm event on air quality in tropicalregions of China

2023年3月中上旬,受北方地区沙尘天气的影响,位处我国热带地区的海南省大部分市县均出现颗粒物浓度骤然升高的现象.为进一步探究我国环境空气质量变化受沙尘天气的影响以及进行颗粒物远距离传输来源解析,本文利用常规大气污染物及气象数据,结合海南边界点位颗粒物组分数据,运用后向轨迹分析、相关性分析等方法研究了此次沙尘过程对海南省环境空气质量的影响及来源分析.结果表明:(1)海南省全省范围内均受到此次沙尘天气不同程度的影响,浮尘由北向南扩散,PM_(10)浓度显著升高.(2)以海口市为例,受沙尘过程影响后,PM_(10)浓度出现明显上升,PM_(2.5)/PM_(10)比值迅速下降,O_(3)、CO、NO_(2)及SO_(2)浓度出现同步上升趋势.(3)沙尘过程造成PM_(10)中化学组分浓度整体升高,其中,硅、铝、硫、钙等地壳元素上升显著,硫元素受本地源及沙尘天气共同影响虽浓度增加但占比降低,氯元素等海盐粒子则与此次过程关系较小;相关性分析得出,铝、硅、钾、钙、锰、铁、铅、钛、锌、磷、硫元素与PM_(10)具有显著相关性,氯元素与大部分元素不具有相关性.本研究表明仍需关注沙尘过程远距离传输对我国热带地区空气质量造成的影响,也为海南省环境空气污染防治精细化治理及预警预报提供了理论依据.

Due to the influence of dust weather in the northern regions,a sudden increase in particulate matter concentration occurred in most counties and cities of Hainan Province,which is in the tropical region of China,in early to mid-March 2023.To explore the impact of dust weather on the China's air quality and analyze the long-distance transmission sources of particulate matter,this study utilized conventional air pollutant data and meteorological data,combined with the particulate matter component data from the boundary station in Hainan,and used the methods of backward trajectory analysis and correlation analysis to study the impact and source analysis of the dust process on the air quality in Hainan Province.The results showed that:①The PM_(10) concentration increased gradually from north to south in Hainan Province,which was affected by the dust weatherfrom different degrees.②In Haikou City,after being affected by the dust process,there was a significant increase in PM_(10) concentration,a rapid decrease in the PM_(2.5)/PM_(10) ratio,and a synchronized increase in O_(3),CO,NO_(2),and SO_(2) concentrations.③The dust weather caused an overall increase in the concentration of chemical components in PM_(10),in which crustal elements such as silicon,aluminum,sulfur,and calcium increased significantly.The sulfur elements were affected by the local sources and dust weather,while the sea salt particles such as chlorine had little relationship with the process.The correlation analysis showed that aluminum,silicon,potassium,calcium,manganese,iron,lead,titanium,zinc,phosphorus,and sulfur were significantly correlated with PM_(10),while chlorine was not correlated with most elements.The study showed that more attention should be paid to the impact of long-distance transport of dust on air quality in tropical areas of China,and it also provided a theoretical basis for the fine control and early warning of ambient air pollution in Hainan Province.