2017年漳州海陆风特征与冬春季污染物浓度关系

利用2017年福建漳州和南部海岛气象观测资料，通过统计分析和人工订正判识海陆风日，再结合天气形势和污染物浓度资料分析海陆风日的天气特征及其与污染物浓度的关系。结果表明：漳州海陆风日是海岛站的2.2倍，春夏季是海陆风的高发季节，秋冬季相对较少。冬季海陆风日主导天气形势为变性冷高压、高压后部、锋前暖区等，气象要素场配置为气压梯度小、气温高、风速小、日照时间长、湿度低、云量少，气象条件不利于污染物的稀释、扩散；海陆风影响下除了O₃，其他5种污染物浓度均高于系统风日2—3倍，其中颗粒物浓度明显偏高。与冬季不同，春季海陆风不仅对颗粒物浓度升高有利，对O₃浓度升高贡献更加明显，主导天气形势、气象要素场配置与冬季类似；海陆风影响下所有污染浓度均高于系统风日1—2倍，且易出现O₃超标现象。研究显示，漳州的海陆风全年发生频率虽然不到30%，但其特有的日变化规律和局地环流结构对污染物累积、输送具有重要的影响。

Characteristics of sea-land breeze and its relationship with pollutant concentrations during winter and spring in 2017 in Zhangzhou

Based on meteorological observational data in Zhangzhou, Fujian province and the south island in 2017, sea-land breeze days were distinguished using statistical analysis and manual correction methods.In combination of synoptic situation and observed pollutant concentrations, the characteristics of sea-land breeze days and its relationship with pollutant concentrations were analyzed.The results show that the number of days with sea-land breeze in Zhangzhou is 2.2 times as large as that observed at an island station.Sea-land breeze occurs more frequently in spring and summer and less in autumn and winter.In winter, synoptic situations on the sea-land breeze days are dominated by transformed surface cold high, high-pressure rear, and warm sector ahead of front, and are accompanied by small pressure gradient, high air temperature, small wind speed, long sunshine duration, low humidity, and small cloud cover, which is unfavorable for the dilution and diffusion of pollutants.During sea-land breeze days, concentrations of all pollutants (except for O₃) are 2-3 times as large as that on the systematic wind days, and particulate matter concentrations are especially high.Unlike in winter, sea-land breeze in spring contributes to high particulate matter and even higher O₃, although the dominated synoptic situation and meteorological conditions in both seasons are similar to each other.All pollutant concentrations on sea-land breeze days are 1-2 times higher than that on systematic wind days, and O₃ concentration is easy to exceed the standard level on sea-land breeze days.Although the annual occurrence frequency of land-sea breeze is less than 30% in Zhangzhou, its unique diurnal variation and local circulation structure have an important impact on pollutant accumulation and transport.