一个检验太阳光度计Langley定标结果可靠性的方法     

董自鹏  余兴  卢娣  戴进  李星敏  陈闯  彭艳  董妍 《大气科学》2020,44(1):39-52

准确反演气溶胶光学厚度（AOD）在气溶胶气候效应和环境效应研究中至关重要，仪器定标是目前AOD反演过程中最大的不确定性来源。Langley法作为应用最广泛的光度计定标方法，其对天气条件和大气洁净度要求苛刻，这在大气污染较重的地区难以实现，并可能导致AOD反演误差偏大。为了降低由不恰当的Langley定标所引起的AOD反演误差，本文提出一个利用辐射传输模式结合地面太阳直接辐射观测数据检验Langley定标结果合理性的方法，并利用西安2013年6月至2015年12月多滤波旋转遮光带辐射计（MFRSR）和直接辐射表（NIP）观测资料，探讨了方法的可行性。结果表明，该方法能够将Langley定标结果限定在较小的波动范围内，有效降低由定标不确定性引起的AOD反演误差，有助于提高单站点AOD观测精度。  相似文献   

Himawari-8气溶胶光学厚度产品的验证分析     

赵垒  辛金元  杨磊库  司瑞瑞  刘光静 《大气科学》2020,44(3):455-471

Himawari-8是由日本气象局发射的新一代静止气象卫星，其搭载的传感器AHI（Advanced Himawari Imager）可实现10 min/次的高时间分辨率对地观测。本文将2015年9月至2017年12月Himawari-8卫星Level-2气溶胶光学厚度（AOD）产品与AERONET（AErosol RObotic NETwork）70个站点的地基观测数据进行对比验证分析，结果表明Himawari-8卫星反演的气溶胶光学厚度产品的精度存在很大的空间上的差异性，其中有48个站点Himawari-8 AOD与AERONET AOD之间存在较好的相关性（R>0.5），有22个站点Himawari-8卫星反演气溶胶光学厚度产品存在明显的低估现象。在American_Samoa、Bandung、Birdsville、Bukit_Kototabang、Canberra、Fowlers_Gap、Jabiru以及QOMS_CAS等站点出现地基观测值很小而卫星反演的气溶胶光学厚度较大的情况。对绝对误差（Himawari-8 AOD与AERONET AOD的差）进行分析发现Himawari-8 AOD存在低估现象时绝对误差与AERONET AOD之间存在较好的相关性；在地基观测值很小而Himawari-8卫星反演AOD较大的地区绝对误差与Himawari-8 AOD之间存在较好的线性关系，这为Himawari-8 AOD反演算法的改进与完善提供了有用的研究发现。  相似文献   

北京地区一次尘暴气溶胶的化学组成及其来源   总被引：3，自引：0，他引：3       下载免费PDF全文

温玉璞  杨绍晋 《应用气象学报》1993,4(3):370-378

讨论了1990年4月25日北京地区出现的一次强尘暴过程的气溶胶特征，探讨了尘暴的来源，从对形成尘暴的气象背景以及尘暴气溶胶中元素资料和稀土元素分布模式的分析，认为该次尘暴气溶胶主要是由形成大风地区及其途经地区的尘土微粒混合组成的。  相似文献   

Some measurements of the extinction coefficients of solar radiation in Lagos     

C. O. Oluwafemi 《Pure and Applied Geophysics》1980,118(2):775-782

Solar radiance measurements covering over seventeen months are analysed for a location beside the Lagos Lagoon. The aerosol extinction coefficient was generally higher in the dusty months than in the wet months. Clean air estimates of the coefficient are made. Data on its wavelength dependence are also presented.  相似文献   

The role of organic material in atmospheric aerosols     

R. Jaenicke 《Pure and Applied Geophysics》1978,116(2-3):283-292

An estimated budget of organic substances in the atmosphere is compiled to whow the importance of organics in the aerosol. The distribution of organic compounds in background aerosols is estimated and it will be shown that the Aitken particles probably consist of roughly one quarter of organic substances. This is important for the dynamics of the aerosol and calculations are presented to estimate the aerosol production distribution for gas-to-particle conversion processes.  相似文献   

Airborne microorganisms: Their occurrence,distribution and dependence on environmental factors — Especially on organic compounds of air-pollution     

Priv.-Doz. Dr. med. H. Rüden  Prof. Dr. med. E. Thofern  Dr. med. P. Fischer  Dr. Ing. U. Mihm 《Pure and Applied Geophysics》1978,116(2-3):335-350

For a period of approximately six months the concentrations of airborne microorganisms were determined by the uptake of their day-characteristic at local places differing by the extent of air pollution. By simultaneously recording the meteorological parameters as temperature, relative humidity, direction and velocity of wind and intensity of solar radiation, it was intended to find out the relationship between these factors and the viability of airborne microorganisms. The present data show an oscillation of the concentration counts over a wide range and seem not yet to depend on the local situation of air pollution.In a further series of experiments the atmospheric aerosol <10 m was collected on air-filters. The decreased substances were extracted from the filter material by aqueous and organic solutants and tested for their antimicrobial activities. In this context the seasonal dependence of the microbicidal activity of organic compounds of aerosol is discussed.  相似文献   

Surface-active substances on rainwater and atmospheric particles     

Winfried Seidl  Gottfried Hänel 《Pure and Applied Geophysics》1983,121(5-6):1077-1093

The surface tension lowering by surface-active substances has been measured on rainwater, melted snow, and dispersions of atmospheric particles in water, with a film balance and a tensiometer. The precipitation water was sampled during 1979, 1980, and 1981 in the city of Frankfurt/Main. From measurements with the film balance technique, normalized concentrations of insoluble and weakly soluble surface-active substances have been estimated. Soluble surface-active substances were determined from measurements with a tensiometer. It was found that the normalized concentration of theinsoluble and weakly soluble surface-active material on rainwater or melted snow shows a maximum during late spring of about 2.5 · 10⁻⁷ moles/l and a minimum during wintertime of about 5 · 10⁻⁸ moles/l. These concentrations are too low to influence significantly the condensation of water vapour on cloud droplets or the evaporation of water from them. Thesoluble surface-active material on rainwater or melted snow was found to have concentrations of the order of 2 · 10⁻⁶ moles/l. These concentrations are also too small to have a significant influence on cloud physical processes.  相似文献   

层积云覆盖的海洋边界层云详细微物理过程的数值模拟   总被引：1，自引：0，他引：1  

赵春生  石坂隆 《气象学报》2004,62(1):87-95

文中建立了一个含显式分档的云微物理模式和辐射传输模式的一维 3阶湍流闭合模式 ,该模式可用于研究海洋边界层云中气溶胶和云的相互作用过程 ,同时提出了一种新的动力模式和微物理模式耦合方法 ,该方法可使动力模式中液态水相关项可以直接由微物理模式变量计算得到。作为模式的初步应用模拟了 2 0 0 1年APEX/ACE Asia在西太平洋上所观测到的一个个例。模拟结果和观测资料比较表明该模式基本上模拟出层积云覆盖的海洋边界层的基本结构  相似文献   

中国近80年来气候变化特征及其形成机制   总被引：157，自引：10，他引：157  

陈隆勋  周秀骥  李维亮  罗云峰  朱文琴 《气象学报》2004,62(5):634-646

自 2 0世纪 2 0年代以来 ,中国地区 4 0和 90年代出现了 2个暖期及 5 0～ 6 0年代相对冷期。最近的 90年代的最暖年 (1998年 )或 5a滑动平均气温几乎已达或略高于 4 0年代的最暖年 (194 6年 )或 5a滑动平均气温。变暖最明显是北方地区 (黑龙江和新疆北部 ) ,而 35°N以南和 10 0°E以东地区自 5 0年代以来存在一个以四川盆地为中心的变冷带 ,虽然 90年代有变暖趋势 ,但基本达到 4 0年代暖期气温。中国降水则以 2 0年代为最少 (192 9年最少 ) ,5 0年代为多水年代 ,以后缓慢减少 ,70年代以后变化不大 ,但多雨带在 80年代及以后由华北南移到长江中下游。195 1～ 1990年 ,大部分地区气温和降水呈负相关 ,在东北和长江—黄河间存在 2个负相关中心 ,表明北方是变暖变旱 ,江淮间是变冷变湿。这些气候变化特征和全球气候变化相比较 ,除北方外 ,变暖期明显的滞后于全球变暖 ,并且出现变冷带等明显差异。文中还综述了用诊断和数值模拟方法对影响中国变化的气候自然变化和人类活动影响 (热岛效应和气溶胶影响 )的研究结果。我们认为 ,以上提出的 3种人类活动对中国气候变化有明显影响 ,特别是工农业发展造成的气溶胶增加是四川盆地气温变冷的主要原因。  相似文献   

Examining the aerosol indirect effect over China using an SO₂ emission inventory     

Kazuaki Kawamoto  Tadahiro Hayasaka  Teruyuki Nakajima  David Streets  Jung-Hun Woo 《Atmospheric Research》2004,72(1-4):353

The relationship between SO₂ emissions and the effective particle radius of low-level water clouds (r_e) over China was investigated to determine anthropogenic effects on clouds. Sulfur dioxide emission values were obtained from a statistical inventory, and r_e origins were retrieved by satellite remote sensing on a 0.5° grid. Comparisons between annual mean SO₂ emissions and r_e showed generally decreasing r_e values, explained by the Twomey effect. The existence of the Twomey effect is supported by comparisons with simulated aerosol optical depths. Results further suggest that clouds over land show sensitivity to the Twomey effect as well as clouds over the ocean.  相似文献