中南半岛地区生物物质燃烧活动使其成为东南亚烟雾气溶胶的高值区,排放的烟雾可以传播到南海海域,影响当地层积云的微观特性和降水活动,进而对气候产生影响。本文利用2007—2019年CALIPSO和CloudSat卫星数据筛选了190个烟雾气溶胶与层...中南半岛地区生物物质燃烧活动使其成为东南亚烟雾气溶胶的高值区,排放的烟雾可以传播到南海海域,影响当地层积云的微观特性和降水活动,进而对气候产生影响。本文利用2007—2019年CALIPSO和CloudSat卫星数据筛选了190个烟雾气溶胶与层积云混合的个例,其中中南半岛等陆地上空(代表陆地)的烟雾混合层积云为88个,南海海域(代表海洋)的烟雾混合层积云为102个。基于个例的研究发现:相对于海洋上的烟雾混合层积云,陆地上的烟雾混合层积云中云的液态粒子数浓度(Number concentration of liquid water drops,LNC)、液态粒子有效半径(Geometric mean radius of liquid water drops,LER)和液态水含量(Liquid water content,LWC)的值都更高。与清洁层积云相比,烟雾气溶胶主要通过半直接效应影响海洋上的层积云,而主要作为云凝结核(Cloud condensation nuclei,CCN)通过间接效应影响陆地上的层积云。当气溶胶光学厚度(Aerosol optical depth,AOD)≤0.6时,海洋上烟雾混合层积云内Twomey效应发挥主导作用,而陆地上烟雾混合层积云内反Twomey效应发挥主导作用;当AOD处于0.6~1.2时,烟雾混合层积云的半直接效应发挥主导作用。本文的研究对中南半岛和南海海域的气溶胶与云的相互作用机制有重要参考意义,并为改进模式结果提供理论支持。展开更多
The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in ...The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in a smog chamber, the gaseous products were detected under the supersonic beam conditions by utilizing vacuum ultraviolet photoionization mass spectrometer using synchrotron radiation in real-time. And an aerosol time-of-flight mass spectrometer was used to provide on-line measurements of the individual secondary organic aerosol particle resulting from irradiating toluene. The experimental results demonstrated that there were some differences between the gaseous products and that of particle-phase, the products of glyoxal, 2-hydroxyl-3-oxo-butanal, nitrotoluene, and methyl-nitrophenol only existed in the particle-phase. However, furane, methylglyoxal, 2-methylfurane, benzaldehyde, cresol, and benzoic acid were the predominant photooxidation products in both the gas phase and particle phase.展开更多
文摘中南半岛地区生物物质燃烧活动使其成为东南亚烟雾气溶胶的高值区,排放的烟雾可以传播到南海海域,影响当地层积云的微观特性和降水活动,进而对气候产生影响。本文利用2007—2019年CALIPSO和CloudSat卫星数据筛选了190个烟雾气溶胶与层积云混合的个例,其中中南半岛等陆地上空(代表陆地)的烟雾混合层积云为88个,南海海域(代表海洋)的烟雾混合层积云为102个。基于个例的研究发现:相对于海洋上的烟雾混合层积云,陆地上的烟雾混合层积云中云的液态粒子数浓度(Number concentration of liquid water drops,LNC)、液态粒子有效半径(Geometric mean radius of liquid water drops,LER)和液态水含量(Liquid water content,LWC)的值都更高。与清洁层积云相比,烟雾气溶胶主要通过半直接效应影响海洋上的层积云,而主要作为云凝结核(Cloud condensation nuclei,CCN)通过间接效应影响陆地上的层积云。当气溶胶光学厚度(Aerosol optical depth,AOD)≤0.6时,海洋上烟雾混合层积云内Twomey效应发挥主导作用,而陆地上烟雾混合层积云内反Twomey效应发挥主导作用;当AOD处于0.6~1.2时,烟雾混合层积云的半直接效应发挥主导作用。本文的研究对中南半岛和南海海域的气溶胶与云的相互作用机制有重要参考意义,并为改进模式结果提供理论支持。
基金This work was supported by the Open Research Fund of Key Laboratory of Atmospheric Composition and Optical Radiation, Chinese Academy of Sciences （No.J J-10-04）, Knowledge Innovation Foundation of Chinese Academy of Sciences （KJCX2-YW-N24）, and the National Natural Science Foundation of China （No.40975080 and No.10979061）.
文摘The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in a smog chamber, the gaseous products were detected under the supersonic beam conditions by utilizing vacuum ultraviolet photoionization mass spectrometer using synchrotron radiation in real-time. And an aerosol time-of-flight mass spectrometer was used to provide on-line measurements of the individual secondary organic aerosol particle resulting from irradiating toluene. The experimental results demonstrated that there were some differences between the gaseous products and that of particle-phase, the products of glyoxal, 2-hydroxyl-3-oxo-butanal, nitrotoluene, and methyl-nitrophenol only existed in the particle-phase. However, furane, methylglyoxal, 2-methylfurane, benzaldehyde, cresol, and benzoic acid were the predominant photooxidation products in both the gas phase and particle phase.
