2025年湖州市空气质量变化特征及冬季一次典型污染过程分析

Analysis of the Air Quality Variation Characteristics and a Typical Winter Pollution Episode in Huzhou City in 2025

摘要: 本研究基于地面气象和空气质量监测数据，结合多源垂直遥感探测资料，分析了2025年湖州市空气质量变化特征，并针对冬季典型污染天气过程，对其气象成因进行深入探讨。湖州市空气质量呈现显著的季节性变化特征，臭氧和颗粒物是影响空气质量达标的关键因子，春末至初秋主要以臭氧为首要污染物，而秋冬季节则主要受颗粒物影响。分析2025年12月16~19日的一次典型PM_2.5污染过程，结果表明，弱冷空气配合静稳、高湿及逆温等不利气象条件是此次污染过程形成的关键驱动因子。天气形势分析和垂直遥感探测资料结果显示：弱冷空气将北方污染物不断输送至湖州，后受均压场控制，颗粒物滞留在湖州地区，在近地面高湿层和逆温层的作用下，促进了颗粒物的吸湿增长与垂直湍流输送，导致PM_2.5浓度的持续增长。

Abstract: Based on ground-based meteorological and air quality monitoring data, combined with multi-source vertical remote sensing observations, the air quality variation characteristics in Huzhou City in 2025 and the meteorological causes of a typical winter pollution episode were analyzed in this study. The air quality in Huzhou exhibited significant seasonal variations, ozone and particulate matters were found to be the key factors affecting air quality. From late spring to early autumn, ozone was the primary pollutant, whereas particulate matters dominated during the autumn and winter seasons. Analysis of a typical PM_2.5 pollution episode from December 16 to 19, 2025 revealed that weak cold air combined with adverse meteorological conditions, including static stability, high humidity, and temperature inversions, were the key driving factors for this pollution event. The ‌synoptic situation and vertical remote sensing analysis results showed that the polluted air masses were transported from northern regions to Huzhou during the cold air period. Subsequently, under the control of a pressure-equalizing field, the particulate matters accumulated in Huzhou. The hygroscopic growth and vertical turbulent transport of particulate matters were promoted due to the high-humidity in the near-surface layer and the existence of the inversion layer, leading to the continuous increase of the PM_2.5 concentrations.