利用统计方法和数值模拟对2008年4月18日-7月28日和2009年5月19日-8月20日在黄山光明顶的两次外场观测中臭氧（O3）数据进行了分析，讨论了中国华东高海拔地区O3的质量浓度特征和来源。结果表明，5、6和7月的月平均质量浓度分别为107．7...利用统计方法和数值模拟对2008年4月18日-7月28日和2009年5月19日-8月20日在黄山光明顶的两次外场观测中臭氧（O3）数据进行了分析，讨论了中国华东高海拔地区O3的质量浓度特征和来源。结果表明，5、6和7月的月平均质量浓度分别为107．73、101．93和68．02μg·m^-1，其中5月和6月的月平均质量浓度相对于国内其他本底站（除上甸子外）以及南极地区高出25～60Iμg·m^-1，7月与其他地区质量浓度相差较少。该地区的0，质量浓度相对于其他地区整体上维持在一个较高的水平，但高质量浓度超标事件发生的次数很少，只占总观测时间的3．9％。质量浓度EI最大值多出现在夜间21时一次日06时（北京时间，下同），呈多峰分布，并且变化幅度很小，在15—20μg·m^-1，通过利用WRF（Weather Research and Forecasting）模式模拟当地上空对流层顶高度和晴空湍流等要素的变化发现，O3质量浓度和对流层顶折叠现象有关。不同天气条件下，其质量浓度在晴天最高，雨天最低，雾天和阴天在二者之间。臭氧质量浓度与温度、相对湿度和其他污染气体（CO、N0和NO3）浓度之间有很强的负相关，而与风速相关性相对较弱；5月北面来风占主导，各风向所对应的O3质量浓度分布较均匀，而6月和7月西南风占主导，北面来向的风对应的质量浓度要高于南面来向。在利用KZ过滤器将O3原始数据分解成不同组份后，发现当地O3质量浓度整体上受低频组份（CBL组份）的控制，其余各高频组份（CSY、CDU和CID组份）只是会使其质量浓度在基准线附近波动。随后对发生在2009年5月28—31日和6月12—15日期间的两次0，质量浓度超标事件中CSY、CDU和CID对基线的贡献做了定量分析。展开更多
In-situ measurements of aerosol optical properties were conducted at Mt. Huang from September 23 to October 28, 2012. Low averages of 82.2, 10.9, and 14.1 Mm-1 for scattering coefficient(σsp, neph, 550), hemispheric ...In-situ measurements of aerosol optical properties were conducted at Mt. Huang from September 23 to October 28, 2012. Low averages of 82.2, 10.9, and 14.1 Mm-1 for scattering coefficient(σsp, neph, 550), hemispheric backscattering coefficient(σhbsp, neph, 550), and absorption coefficient(σap, 550), respectively, were obtained. Atmospheric aging process resulted in the increase of σap, 550 but the decrease of the single scattering albedo(ω550) at constant aerosol concentration. However, the proportion of non-light-absorbing components(non-BCs) was getting higher during the aging process, resulting in the increase of aerosol diameter, which also contributed to relatively higher σsp, neph, 550 and ω550. Diurnal cycles of σsp, neph, 550 and σap, 550 with high values in the morning and low values in the afternoon were observed closely related to the development of the planetary boundary layer and the mountain-valley breeze. BC mixing state, represented by the volume fraction of externally mixed BC to total BC(r), was retrieved by using the modified Mie model.The results showed r reduced from about 70% to 50% when the externally mixed non-BCs were considered. The periodical change and different diurnal patterns of r were due to the atmospheric aging and different air sources under different synoptic systems. Local biomass burning emissions were also one of the influencing factors on r. Aerosol radiative forcing for different mixing state were evaluated by a "two-layer-single-wavelength" model,showing the cooling effect of aerosols weakened with BC mixing state changing from external to core-shell mixture.展开更多
文摘利用统计方法和数值模拟对2008年4月18日-7月28日和2009年5月19日-8月20日在黄山光明顶的两次外场观测中臭氧（O3）数据进行了分析，讨论了中国华东高海拔地区O3的质量浓度特征和来源。结果表明，5、6和7月的月平均质量浓度分别为107．73、101．93和68．02μg·m^-1，其中5月和6月的月平均质量浓度相对于国内其他本底站（除上甸子外）以及南极地区高出25～60Iμg·m^-1，7月与其他地区质量浓度相差较少。该地区的0，质量浓度相对于其他地区整体上维持在一个较高的水平，但高质量浓度超标事件发生的次数很少，只占总观测时间的3．9％。质量浓度EI最大值多出现在夜间21时一次日06时（北京时间，下同），呈多峰分布，并且变化幅度很小，在15—20μg·m^-1，通过利用WRF（Weather Research and Forecasting）模式模拟当地上空对流层顶高度和晴空湍流等要素的变化发现，O3质量浓度和对流层顶折叠现象有关。不同天气条件下，其质量浓度在晴天最高，雨天最低，雾天和阴天在二者之间。臭氧质量浓度与温度、相对湿度和其他污染气体（CO、N0和NO3）浓度之间有很强的负相关，而与风速相关性相对较弱；5月北面来风占主导，各风向所对应的O3质量浓度分布较均匀，而6月和7月西南风占主导，北面来向的风对应的质量浓度要高于南面来向。在利用KZ过滤器将O3原始数据分解成不同组份后，发现当地O3质量浓度整体上受低频组份（CBL组份）的控制，其余各高频组份（CSY、CDU和CID组份）只是会使其质量浓度在基准线附近波动。随后对发生在2009年5月28—31日和6月12—15日期间的两次0，质量浓度超标事件中CSY、CDU和CID对基线的贡献做了定量分析。
基金supported by the National Key Research and Development Program of China(2016YFC0203500,Task#1 and2016YFA0602004)the National Science Foundation of China(NSFC)(Nos.41590873,41030962)
文摘In-situ measurements of aerosol optical properties were conducted at Mt. Huang from September 23 to October 28, 2012. Low averages of 82.2, 10.9, and 14.1 Mm-1 for scattering coefficient(σsp, neph, 550), hemispheric backscattering coefficient(σhbsp, neph, 550), and absorption coefficient(σap, 550), respectively, were obtained. Atmospheric aging process resulted in the increase of σap, 550 but the decrease of the single scattering albedo(ω550) at constant aerosol concentration. However, the proportion of non-light-absorbing components(non-BCs) was getting higher during the aging process, resulting in the increase of aerosol diameter, which also contributed to relatively higher σsp, neph, 550 and ω550. Diurnal cycles of σsp, neph, 550 and σap, 550 with high values in the morning and low values in the afternoon were observed closely related to the development of the planetary boundary layer and the mountain-valley breeze. BC mixing state, represented by the volume fraction of externally mixed BC to total BC(r), was retrieved by using the modified Mie model.The results showed r reduced from about 70% to 50% when the externally mixed non-BCs were considered. The periodical change and different diurnal patterns of r were due to the atmospheric aging and different air sources under different synoptic systems. Local biomass burning emissions were also one of the influencing factors on r. Aerosol radiative forcing for different mixing state were evaluated by a "two-layer-single-wavelength" model,showing the cooling effect of aerosols weakened with BC mixing state changing from external to core-shell mixture.
