中国海洋上空细粒子气溶胶与短寿命痕量气体的时空关系

Temporal and spatial relationship between fine particle aerosols and short-lived trace gas in Chinese ocean

定量分析气溶胶与痕量气体之间的时空变化关系有助于进一步研究气粒转化。本文采用2006年—2015年MODIS气溶胶光学厚度(AOD)、细粒子模态比(FMF)和OMI痕量气体(SO2、NO2和HCHO)数据,对黄海、东海和南海区域上空的细粒子气溶胶与痕量气体进行定量分析。先对气溶胶和痕量气体作均值分析发现:AODfine、SO2、NO2和HCHO的均值在黄海、南海、东海均依次减小;再对气溶胶对痕量气体的敏感度分析发现:黄海地区的AODfine对SO2最敏感,敏感度为0.424,这与中国东部沿海城市的人为排放有关;而东海和南海地区对HCHO的敏感度较高,依次为0.664和0.545,主要受东南亚和中国南方地区生物质燃烧影响。最后,对3个区域的气溶胶与痕量气体按季节作相关性分析发现:黄海地区AODfine在夏秋两季与SO2的相关性较强(R>0.5),主要由于夏秋两季的温湿度大,利于发生气—粒转化;东海地区夏季HCHO与AODfine相关性较明显(R=0.57);南海春季HCHO与AODfine相关性较好(R=0.57),呈现出区域与季节性的变化。最终发现,气溶胶与痕量气体随着时空变化存在相关关系。

Aerosols have important effects on global energy balance, cloud properties, rainfall frequency, and atmospheric circulation. To understand the impact of aerosols on climate change, this paper explores the quantitative relationship between fine particle aerosols and gases.Aerosol Optical Depth(AOD), Fine Mode Fraction(FMF) from MODIS, and trace gas(SO2, NO2, and HCHO) from OMI were used to analyze the quantitative relationship between the fine aerosols and trace gases over the Yellow Sea, East China Sea, and South China Sea between 2006 and 2015.First, the mean values of the aerosols and trace gases were analyzed. The mean values of AODfine, SO2, NO2, and HCHO decreased orderly in the Yellow Sea, South China Sea, and East China Sea all decreased. Meanwhile, the sensitivity analysis of the relationship between aerosols and trace gases revealed that: AODfine is most sensitive to SO2 with a sensitivity of 0.424, which may be ascribed to the anthropogenic emissions from the coastal cities of Eastern China. Meanwhile, East China Sea and South China Sea demonstrate high sensitivity to HCHO(0.664 and 0.545, respectively), which can be ascribed to the biomass combustion in Southeast Asia and Southern China. The seasonal correlation analysis of aerosols and trace gases in these three regions reveal that the AODfine in the Yellow Sea has a strong correlation with SO2 during summer and autumn(R>0.5) mainly due to the high temperature and humidity. A significant correlation is observed between HCHO and AODfine was significant in the East China Sea(R=0.57), and a relatively good correlation is observed between HCHO and AODfine in the South China Sea was relatively good(R=0.57) due to regional and seasonal changes.In sum,fine particle modal aerosol has a significant correlation with trace gases, and such relationship provides a scientific basis for understanding the aerosol processes, especially those of artificial aerosols dominated by fine particles.