采用CERES SSFAqua MODIS Edition 2B/2C和CALIPSO卫星探测资料结合地面台站沙尘观测资料,通过对强沙尘天气过程中纯云区与沙尘云区大气层顶处辐射强迫值的对比分析,研究了我国华北地区沙尘气溶胶对云辐射强迫的影响.研究发现,2006年4...采用CERES SSFAqua MODIS Edition 2B/2C和CALIPSO卫星探测资料结合地面台站沙尘观测资料,通过对强沙尘天气过程中纯云区与沙尘云区大气层顶处辐射强迫值的对比分析,研究了我国华北地区沙尘气溶胶对云辐射强迫的影响.研究发现,2006年4月16日、5月16日、2007年3月30日3次过程沙尘云区大气层顶云的净辐射强迫绝对值比纯云区分别减小了7.1%,17.2%和3.1%,云的冷却效应受到不同程度抑制.纯云区与沙尘云区云的光学特性参量的对比分析结果表明,绝大部分沙尘云区的云粒径、云水路径和光学厚度值均比纯云区的要小.展开更多
采用AERONET Version 2 Level 2.0气溶胶数据集,分析了光学厚度、Angstrom波长指数、粒子尺度体积谱分布(dV(r)/dlnr)、折射指数(n-ik)和单次散射反照率(ω0)等大气气溶胶光学特性参数的季节变化特征以及光谱依赖性。结果表明:气溶胶特...采用AERONET Version 2 Level 2.0气溶胶数据集,分析了光学厚度、Angstrom波长指数、粒子尺度体积谱分布(dV(r)/dlnr)、折射指数(n-ik)和单次散射反照率(ω0)等大气气溶胶光学特性参数的季节变化特征以及光谱依赖性。结果表明:气溶胶特性参量均具有明显的季节变化且呈现出明显的受沙尘影响的特征,春季受沙尘影响最明显,光学厚度最大;冬季受采暖和沙尘的共同影响,光学厚度也较大。气溶胶粒子体积尺度谱分布的主要差别体现在粗模态粒子体积浓度上,粗模态体积浓度呈现明显的季节变化规律:春季>冬季>夏季>秋季,与粗细粒子体积浓度比和光学厚度变化一致,说明该地区光学厚度的季节变化主要是由于粗模态体积浓度不同造成的。另外,粗模态体积中值半径也存在明显的季节变化:冬季>秋季>夏季>春季。折射指数实部和气溶胶粗粒子体积浓度与光学厚度的季节变化规律一致,而折射指数虚部冬季最大,春季最小;单次散射反照率随季节的变化规律有很大不同,冬季最小,而春季最大,可能与气溶胶粒子尺度及其化学组成的综合作用有关。展开更多
Some field experiments of aerosols had been carried out over the arid and semi-arid regions in China over the past 30 years,but there were little learning of the semi-arid region of Loess Plateau.Using Version 2.0 Lev...Some field experiments of aerosols had been carried out over the arid and semi-arid regions in China over the past 30 years,but there were little learning of the semi-arid region of Loess Plateau.Using Version 2.0 Level 2.0 dataset from the AERONET(Aerosol Robotic Network)Lanzhou_city site,the aerosol optical properties during dusty and non-dusty periods in winter and spring when air pollution frequently occured most frequently were demonstrated.A comparison of the same parameters between Lanzhou and Beijing for spring was also analyzed.Some new information was gained concerning aerosol optical properties over the semi-arid region of Loess Plateau.The results show that the aerosol properties measured during dusty and non-dusty periods are significantly different at Lanzhou,particularly in spring,and also different from those at Beijing.展开更多
The seasonal variability of cloud optical depth over northwestern China derived from Clouds and the Earth＇s Radiant Energy System （CERES） Single Scanner Footprint （SSF） Aqua Moderate Resolution Imaging Spectrorad...The seasonal variability of cloud optical depth over northwestern China derived from Clouds and the Earth＇s Radiant Energy System （CERES） Single Scanner Footprint （SSF） Aqua Moderate Resolution Imaging Spectroradiometer （MODIS） Edition IB data from July 2002 to June 2004 is presented. The regions of interest are those with Asia monsoon influence, the Tianshan and Qilian Mountains, and the Taklimakan Desert. The results show that the instantaneous measurements presented here are much higher than the previous results derived from International Satellite Cloud Climatology Project （ISCCP） D2 monthly mean data. Generally the measurements of cloud optical depth are the highest in summer and the lowest in winter, however, Taklimakan Desert has the lowest measurements in autumn. The regional variation is quite significant over northwestern China.展开更多
文摘采用CERES SSFAqua MODIS Edition 2B/2C和CALIPSO卫星探测资料结合地面台站沙尘观测资料,通过对强沙尘天气过程中纯云区与沙尘云区大气层顶处辐射强迫值的对比分析,研究了我国华北地区沙尘气溶胶对云辐射强迫的影响.研究发现,2006年4月16日、5月16日、2007年3月30日3次过程沙尘云区大气层顶云的净辐射强迫绝对值比纯云区分别减小了7.1%,17.2%和3.1%,云的冷却效应受到不同程度抑制.纯云区与沙尘云区云的光学特性参量的对比分析结果表明,绝大部分沙尘云区的云粒径、云水路径和光学厚度值均比纯云区的要小.
文摘采用AERONET Version 2 Level 2.0气溶胶数据集,分析了光学厚度、Angstrom波长指数、粒子尺度体积谱分布(dV(r)/dlnr)、折射指数(n-ik)和单次散射反照率(ω0)等大气气溶胶光学特性参数的季节变化特征以及光谱依赖性。结果表明:气溶胶特性参量均具有明显的季节变化且呈现出明显的受沙尘影响的特征,春季受沙尘影响最明显,光学厚度最大;冬季受采暖和沙尘的共同影响,光学厚度也较大。气溶胶粒子体积尺度谱分布的主要差别体现在粗模态粒子体积浓度上,粗模态体积浓度呈现明显的季节变化规律:春季>冬季>夏季>秋季,与粗细粒子体积浓度比和光学厚度变化一致,说明该地区光学厚度的季节变化主要是由于粗模态体积浓度不同造成的。另外,粗模态体积中值半径也存在明显的季节变化:冬季>秋季>夏季>春季。折射指数实部和气溶胶粗粒子体积浓度与光学厚度的季节变化规律一致,而折射指数虚部冬季最大,春季最小;单次散射反照率随季节的变化规律有很大不同,冬季最小,而春季最大,可能与气溶胶粒子尺度及其化学组成的综合作用有关。
基金National Natural Science Foundation of China(No.40975012)Foundation of Key Laboratory for Semiarid Climate Change of Ministry of Education in Lanzhou University and Fundamental Research Funds for the Central Universities,China(No.223-860011)National Basic Research Programof China(No.2011CB403405)
文摘Some field experiments of aerosols had been carried out over the arid and semi-arid regions in China over the past 30 years,but there were little learning of the semi-arid region of Loess Plateau.Using Version 2.0 Level 2.0 dataset from the AERONET(Aerosol Robotic Network)Lanzhou_city site,the aerosol optical properties during dusty and non-dusty periods in winter and spring when air pollution frequently occured most frequently were demonstrated.A comparison of the same parameters between Lanzhou and Beijing for spring was also analyzed.Some new information was gained concerning aerosol optical properties over the semi-arid region of Loess Plateau.The results show that the aerosol properties measured during dusty and non-dusty periods are significantly different at Lanzhou,particularly in spring,and also different from those at Beijing.
基金the National Natural Science Foundation of China(No.40633017 and 40575036)the National"973"Program of China(No.2006CB403700)The data were obtained from the NASA Langley Research Center Atmospheric Sciences Data Center.We appreciate Dr.Yuhong Yi for helping us with data and Mr.Jim Miller for smoothing the English+1 种基金Funding for the processing of the northwestern China data was provided by the Special Professional Outlay for Scientific Research for Commonweal(No.GYHY(QX)2007)the Shanghai Leading Academic Discipline Project(No.B604)
文摘The seasonal variability of cloud optical depth over northwestern China derived from Clouds and the Earth＇s Radiant Energy System （CERES） Single Scanner Footprint （SSF） Aqua Moderate Resolution Imaging Spectroradiometer （MODIS） Edition IB data from July 2002 to June 2004 is presented. The regions of interest are those with Asia monsoon influence, the Tianshan and Qilian Mountains, and the Taklimakan Desert. The results show that the instantaneous measurements presented here are much higher than the previous results derived from International Satellite Cloud Climatology Project （ISCCP） D2 monthly mean data. Generally the measurements of cloud optical depth are the highest in summer and the lowest in winter, however, Taklimakan Desert has the lowest measurements in autumn. The regional variation is quite significant over northwestern China.
