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51.
R. G. Derwent W. J. Collins M. E. Jenkin C. E. Johnson D. S. Stevenson 《Journal of Atmospheric Chemistry》2003,44(1):57-95
A global 3-D Lagrangian chemistry-transport model STOCHEM is used to describe the tropospheric distributions of four components of the secondary atmospheric aerosol: nitrate, sulphate, ammonium and organic compounds. The model describes the detailed chemistry of the formation of the acid precursors from the oxidation of SO2, DMS, NOx, NH3 and terpenes and their uptake into the aerosol. Model results are compared in some detail with the available surface observations. Comparisons are made between the global budgets and burdens found in other modelling studies. The global distributions of the total mass of secondary aerosols have been estimated for the pre-industrial, present day and 2030 emissions and large changes have been estimated in the mass fractions of the different secondary aerosol components. 相似文献
52.
MODELING THE EFFECTS OF ANTHROPOGENIC SULFATE IN CLIMATE CHANGE BY USING A REGIONAL CLIMATE MODEL 总被引:3,自引:2,他引:3
1 INTRODUCTION Being an important composition of the atmosphere, aerosol attracts increasing attention from the scientific community in recent years, together with the radiative forcing it causes and effects it imposes on the climate system. The anthropogenic aerosol affects the climate both directly and indirectly. The climate is directly affected when solar shortwave radiation is scattered and absorbed in what is known as the 搖mbrella effect? which can be dated back to as early as mor… 相似文献
53.
大气气溶胶光学厚度的宽带消光遥感方法及其应用 总被引:6,自引:1,他引:6
该文发展了遥感气溶胶光学厚度的一个宽带消光遥感方法 ,它应用地面上太阳直射表探测的宽波段太阳直射信息反演 0 75 μm大气柱光学厚度。这方法的主要误差因子是气溶胶谱的不确定性。数值试验表明 ,气溶胶谱分布的误差所引起光学厚度解的误差一般小于 5 %。 1995年 1— 10月进行的 12 6 7组对比实验表明 ,由本方法探测的气溶胶光学厚度与光度计探测的气溶胶光学厚度的标准差为 10 5 % ,两者平均结果的偏差只有 0 7%。该文还应用这个方法 ,从气象台站辐射观测资料反演得到北京、沈阳等 10个地方 1980— 1994年间晴天气溶胶光学厚度资料 ,并分析其变化规律 相似文献
54.
采自新疆哈图金矿区各地层单元和含矿脉体中的基岩人工重砂样品普遍含有一种“微球粒”物质。通过“微球粒”的一般特征,表面、断面结构、矿物组成和化学成分的研究,认为属消融型宇宙尘。并据此提出区内玄武质母岩浆在形成玄武岩的过程中同化、熔融了含宇宙尘的局部老地层物质;为区内金矿化提供含矿热液的花岗岩属重熔型花岗岩。 相似文献
55.
56.
中国西北部“4.5”沙尘暴过程中尺度低压的数值模拟 总被引:3,自引:9,他引:3
利用改进型PSU/NCAR中尺度数值模式(MM4标准版),取模式水平格距40km,46×61网格,垂直方向a取15层,即从地面到模式顶(100hPa),σ=0.0、0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.78、0.84、0.89、0.93、0.96、0.98、0.99、1.00,采用NCAR的30'×30'地形资料,以常规观测资料作为初始场,较好地模拟了此次沙尘暴过程的海平面气压的演变和分布,特别是张掖、柴达本盆地以及敦煌附近的三个中低压。同时,模拟了张掖中低压与蒙古冷高压之间的甘肃河西沙尘暴东大风。敏感性试验表明,沙尘暴中低压的形成发展主要是受于物理过程制约;沙尘暴中尺度系统的研究与暴雨中尺度系统的研究是有区别的,积云对流参数化并不是特别重要,在设计研究沙尘暴的数值模式中,应当合理地处理其他的热力、动力过程及大气外强迫源的作用。模式水平格距、地形真实程度对模拟中低压的位置、中心强度有重要贡献;下垫面变化中低压强度有一定影响。张掖热低压的形成发展主要是在有利的环境形势下,特殊地势起了重要作用,表现为直接动力强迫和间接热力强迫。 相似文献
57.
The time evolution of stratospheric aerosol layer formed after a volcanic eruption is studied taking into account the aerosol
microphysical processes of growth, coagulation and sedimentation. Using a simple model we could explain the observed evolution
of the Pinatubo volcanic layer which decayed in about 3 years. The experimental data obtained by Nd:YAG backscatter lidar
over Ahmedabad further supports this finding. The data obtained after the El Chichon volcanic eruption also showed that the
El Chichon aerosol layer decayed in about 3 years time. Thus, though the amount of SO2 injected has been higher, in the case of Pinatubo, about two to three times more than El Chichon, it has resulted in the
production of larger aerosol particles due to faster growth and coagulation processes, and subsequently a faster removal rate,
to give more or less a similar background aerosol amount at the stratosphere in about 3 years time. 相似文献
58.
Magnetostratigraphy and palaeoclimate of Red Clay sequences from Chinese Loess Plateau 总被引:5,自引:0,他引:5
Two Red Clay profiles near Xi’an and Xifeng were investigated in an attempt to determine magnetostratigraphic and palaeoclimatic
records. The results show that aeolian dust accumulation and the related East Asia palaeomonsoon system had begun by 6.5 Ma,
and it is deduced that the Tibetan Plateau had reached a significant elevation at that time. The late Tertiary palaeoclimatic
history of the Red Clay as reflected by magnetic susceptibility is reconstructed during the period of 6.5–2.5 Ma. Stepwise
increase in susceptibility of aeolian dust accumulation appears to have a close correlation to the uplift processes of the
Tibetan Plateau. The remarkable increase of aeolian dust accumulation at 3.2 Ma appears to be due to the influence of global
ice volume on the East Asia monsoon. Palaeomonsoon variation during the late Tertiary as recorded in the Red Clay sequences
from the Chinese Loess Plateau can be regarded as the product of a number of interacting factors, such as uplift of the Tibetan
Plateau, solar radiation, global ice volume, etc.
Project supported by the National Natural Science Foundation of China and the Foundation of Xi’an Laboratory of Loess and
Quaternary Geology, Chinese Academy of Sciences. 相似文献
59.
古里雅冰帽8米浅冰芯的化学成分组成特征及其来源 总被引:10,自引:3,他引:10
对古里雅冰帽8m浅冰芯的80个雪冰样品化学分析结果表明,化学成分主要来自陆源物质,陆源冰芯样品叶弱碱性,明显不同于一般的大气降水及南北极冰雪样品。 相似文献
60.
1 INTRODUCTION Sitting in the central part of the Pearl River Delta, Guangzhou is one of the cities in China that are most polluted by acid rain. Broad attention has been brought to the problem. Since the early 1980s, a series of observation and studies h… 相似文献