Scattering Properties of Atmospheric Aerosols over Lanzhou City and Applications Using an Integrating Nephelometer     

ZHANG Wu  HU Bo  CHEN Changhe  DU Ping  ZHANG Lei  FENG Guanghong 《大气科学进展》2004,21(6):848-856

The data, measured by a three-wavelength Integrating Nephelometer over Lanzhou City during the winters of 2001/2002 and 2002/2003 respectively, have been analyzed for investigating the scattering properties of atmospheric aerosols and exploring their relationship and the status of air pollution. The aerosol particle volume distribution is inverted with the measured spectral scattering coefficients. The results show that the daily variation of the aerosol scattering coefficients is in a tri-peak shape. The average ratio of backscattering coefficient to total scattering coefficient at 550 nm is 0.158; there exists an excellent correlation between the scattering coefficients and the concentration of PM10. The average ratio of the concentration of PM10 to the scattering coefficients is 0.37g m^-2, which is contingent on the optical parameters of aerosol particles such as the size distribution, etc.; an algorithm is developed for inverting the volume distribution of aerosol particles by using the histogram and Monte-Carlo techniques, and the test results show that the inversion is reasonable.  相似文献   

The physics of thundercloud and lightning discharge. Comment on the note by Earle Williams and Sharon Stanfill The physical origin of the land–ocean contrast in lightning activity     

Constantin Pontikis  Elizabeth Hicks  Nathalie Michalon 《Comptes Rendus Geoscience》2004,336(15):1409-1412

The arguments and conclusions of the commented Williams and Stanfill article in relation to the validity of the thermal and aerosol hypotheses advanced in order to explain the land–ocean contrast in lightning activity are critically re-examined. This re-examination reveals that the analysis presented by these authors is incomplete, thus weakening the corresponding conclusions. To cite this article: C. Pontikis et al., C. R. Geoscience 336 (2004).  相似文献   

Physical properties of aerosols at Maitri,Antarctica     

C. G. Deshpande  A. K. Kamra 《Journal of Earth System Science》2004,113(1):1-25

Measurements of the submicron aerosol size distribution made at the Indian Antarctic station, Maitri (70‡45′S, 11‡44′E) from January 10th to February 24th, 1997, are reported. Total aerosol concentrations normally range from 800 to 1200 particles cm⁻³ which are typical values for the coastal stations at Antarctica in summer. Aerosol size distributions are generally trimodal and open-ended with a peak between 75 and 133 nm and two minima at 42 and 420 nm. Size distributions remain almost similar for several hours or even days in absence of any meteorological disturbance. Total aerosol concentration increases by approximately an order of magnitude whenever a low pressure system passes over the station. Based on the evolution of aerosol size-distributions during such aerosol enhancement periods, three types of cases have been identified. The nucleation mode in all three cases has been suggested to result from the photochemical conversion of the DMS emissions transported either by the marine air or by the air from the ice-melt regions around Maitri. Subsidence of midtropospheric air during the weakening of radiative inversion is suggested as a possible source of the nucleation mode particles in the third case. Growth of the nucleation mode particles by condensation, coagulation and/or by cloud processes has been suggested to be responsible for other modes in size distributions.  相似文献   

硫酸盐气溶胶直接辐射效应在线与离线模拟方法的比较   总被引：3，自引：0，他引：3  

吴涧  蒋维楣  刘红年  王卫国  罗燕 《气象学报》2004,62(4):486-492

利用区域气候模式RegCM 2与大气化学模式连接的模拟系统 ,比较了硫酸盐气溶胶辐射强迫的在线、离线模拟方法的硫酸盐柱含量、大气顶直接辐射强迫及地表温度响应。发现 :在线与离线模拟方法得到的硫酸盐柱含量、有无反馈大气顶直接辐射强迫和地表温度响应在许多地区有很大差异 ,这种差异在较小区域平均的尺度上更显著 ,在全区域平均尺度上也较为明显 ,是不能被忽略的 ;结果显示从硫酸盐含量到辐射强迫和地表温度响应逐渐加大的差异 ,说明硫酸盐气溶胶的辐射强迫与模拟方法有关 ,显示出较大的不确定性。  相似文献   

渤海西岸气溶胶光学厚度测量研究   总被引：6，自引：0，他引：6  

高润祥  张文煜 《沙漠与绿洲气象(新疆气象)》2004,27(6):19-21,25

根据2003年在天津大气边界层观测站获得的CE318太阳光度计观测资料，探讨了仪器的定标、渤海西岸大气气溶胶不同波段的光学厚度及其变化规律。结果表明，渤海西岸大气气溶胶受渤海海洋和人类活动共同影响，各波段光学厚度都较大；气溶胶光学厚度谱基本满足Angstrom关系。  相似文献   

北京地区气溶胶粒度谱分布初步研究   总被引：12，自引：0，他引：12  

Zhang Renjian  Wang Mingxing  Fu Jianzhong 《大气科学进展》2001,18(2):225-230

本文对北京地区气溶胶数浓度及其诸分布特征进行了初步研究。重点探讨了气溶胶数浓度分布与相对湿度的关系。研究结果表明，气溶胶浓度和谱分布存在明显的日变化和逐日变化，并在很大程度上受空气相对湿度和理查森数影响。  相似文献   

贺兰山地区春季沙尘气溶胶质量浓度的观测分析   总被引：41，自引：4，他引：41  

牛生杰  孙继明  陈跃  刘宏杰 《高原气象》2001,20(1):82-87

通过对贺兰山地区大气背景、浮尘、扬沙和沙尘暴天气的采样，得到在不同天气条件下的气溶胶质量浓度，而且在它们之间存在一定的倍数关系。由Anderson和KB－120E采样器得到的总浓度是有差异的。  相似文献   

华东地区大气本底条件下大气透明度的变化特点   总被引：1，自引：0，他引：1  

洪盛茂 《气象》1996,22(9):10-14

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高光谱分辨率激光雷达同时测量大气风和气溶胶光学性质的模拟研究   总被引：3，自引：3，他引：3       下载免费PDF全文

刘金涛  陈卫标  刘智深 《大气科学》2003,27(1):115-122

提出一套高光谱分辨率激光雷达(HSRL)系统,用于同时测量大气风和气溶胶的光学性质.该HSRL系统中使用碘分子滤波器分离分子和气溶胶后向散射,同时利用双边缘检测技术测量大气风场引起的多普勒频移.文中选用合理的HSRL参数和大气模型数据,模拟和分析了HSRL的测量性能.系统夜晚运行时,可测量20 km以下的大气风速和气溶胶,风速误差小于2 m s-1,气溶胶的后向散射系数相对误差小于30%.在白天工作时,相同误差下的可探测高度为10 km.模拟分析结果表明,该HSRL雷达有较大的应用前景,对天气和气象研究等有重要意义.  相似文献   

China‘s First Exploration of Chukchi Sea and Its Adjacent Waters in the Arctic -A Study on Lead Geochemistry of Atmospheric Aerosol     

朱赖民  陈立奇 《中国地球化学学报》2003,22(1):23-29

The Pb concentrations of atmospheric aerosol in the Chukchi Sea of the Arctic vary within the range of 0.167-0.962ng/m^2,with an average of 0.532ng/m^3,These concentration values are 200 times higher than the natural background values of snow samples there.Calculation of the Pb enrichment factor of aerosol indicates that the ocean-and continent-source lead account for 9.23% and 0.01%,respectively,but industrially released Pb accounts for more than 90% of the atmospheric Pb.The Pb isotopic composition of aerosol has revealed that the sources of lead from industrial lead that causes pollution include mainly the western part of North America,East Europe and the former Soviet union.The calculation of the total fallout flux of Pb indicates that the mean value of input flux into the Chukchi Sea is 0.02mgm^-2a^-1,equivalent to that of southern Pacific but slightly lower than that of northern Indian Sea and southern Atlantic.It is evidenced that the Pb input flux into the Chukchi Sea is far lower than that off the Baltic Sea,the North Sea and the Mediterranean Sea.  相似文献