Particulate carbon content in rain at various temperate and tropical locations     

Joelle Ducret  Helene Cachier 《Journal of Atmospheric Chemistry》1992,15(1):55-67

Particulate organic and black carbon concentrations in rain were determined in various source or remote regions, in order to gain information on the incorporation of atmospheric carbonaceous particles in hydrometeors. The analyses of rainwaters indicate that all the samples contained particles derived from combustion. Data obtained on a sample basis, show an important areal and temporal variability of the composition of rain carbonaceous particles, a variability which is reported to that of the black carbon to total carbon ratio, Cb/Ct, ranging from 10 to 72%. In addition to the fluctuations of the aerosol atmospheric burden, these variations may be related to alterations of the organic fraction of the particles or their involvement in in-cloud nucleation processes during atmospheric transport. Also, a comparison of the mean relative abundance of black carbon in aerosols and in rainwaters, gives evidence of a partial disappearance of the organic particles, a phenomenon which could be due to their dissolution when incorporated in the hydrometeors. Precipitation scavenging ratio values of black carbon particles, which range from 100 to 370, are similar to those found for sulphate anthropogenic aerosols. Due to their hygroscopic properties and mean size, black carbon aerosols could possibly trace the physico-chemical processes involved in the incorporation of fine combustion particles into hydrometeors. It is also suggested that smoke particles may act as cloud condensation nuclei (CCN). Consequently, emissions of particulates derived from combustion in some tropical or industrial regions could result locally in alteration of cloud albedo and precipitation regimes.  相似文献   

云下雨滴蒸发产生硫酸盐气溶胶速率的研究     

刘小红  任传森  王明康 《大气科学》1994,18(3):348-357

云下雨滴蒸发是雨滴下降过程中重要的物理过程，特别是当云下相对湿度较低时更为明显。本文建立了考虑雨滴蒸发的云下雨水酸化的物理化学模式，用以研究云下雨滴蒸发作用对各种大小雨滴及雨水酸化的影响，并估算了由于小雨滴的完全蒸发进入到大气中的硫酸盐气溶胶的生成速率。计算结果表明:这种小雨滴的完全蒸发使雨滴内化学反应生成的硫酸盐结晶进入大气，在降水初期云下相对湿度较小时，形成硫酸盐气溶胶的速率可达1% h-1，与气粒转化速率相当。  相似文献   

环球海洋大气气溶胶化学研究 III：金属形态和入海通量   总被引：8，自引：0，他引：8  

陈立奇  余群  杨绪林 《大气科学》1994,18(2):215-223

中国第三次南极考察和环球科学考察，历经北太平洋、南太平洋、南极半岛海域、南大西洋、北印度洋、以及沿途近岸海域，共收集58个气溶胶样品，采用石墨炉原子吸收法分析其中的水可溶态和酸可溶态的Mn、Fe、Pb、Cu、Cd。气溶胶中金属表现明显陆源向大洋输送的浓度梯度，近岸海域上空金属含量大于大洋上空含量，北太平洋上空含量高于南太平洋和南极半岛海域。气溶胶中金属的水可溶程度，在近岸海域上空依次为Cd＞Mn＞Cu＞Fe＞Pb，百分比分量分别为39%，36%， 23%，14%和5.3%；在大洋上空依次为Cd＞Mn＞Fe＞Cu＞pb，百分比分量分别为62%，44%，11%，3.1%和2.5%。本文还计算和比较各观测海区上空金属从大气输入海水的通量。  相似文献   

GROUND-BASED REMOTE SENSING OF THE SIZE DISTRIBUTION OF PINATOBU''''S VOLCANIC CLOUD          下载免费PDF全文

吕达仁  刘锦丽  李放 《Acta Meteorologica Sinica》1994,(1)

In this paper,data of solar direct spectral radiance observation in summer and autumn of 1990 and 1991 were usedto derive the average atmospheric extinction spectra for very clear days each year.The difference of these two extinctionspectra is obvious and considered as the contribution of volcanic cloud resulting from Pinatobu's volcanic eruption inmiddle June of 1991.This average size distribution of volcanic cloud was retrieved from the difference spectra and givenin this paper which will be useful for estimation and modeling of the effects of volcanic eruption.  相似文献   

The solubility and behaviour of acid gases in the marine aerosol     

P. Brimblecombe  S. L. Clegg 《Journal of Atmospheric Chemistry》1988,7(1):1-18

The following Henry's law constants (K _H/mol²kg^-2atm^-1) for HNO₃ and the hydrohalic acids have been evaluated from available partial pressure and other thermodynamic data from 0°–40°C, 1 atm total pressure: HNO ₃ , 40°C–5.85×10⁵; 30°C–1.50×10⁶; 25°C–2.45×10⁶; 20°C–4.04×10⁶; 10°C–1.15×10⁷; 0°C–3.41×10⁷. HF, 40°C–3.2; 30°C–6.6; 25°C–9.61; 20°C–14.0; 10°C–32.0; 0°C–76. HCl, 40°C–4.66×10⁵; 30°C–1.23×10⁶; 25°C–2.04×10⁶; 20°C–3.37×10⁶; 10°C–9.71×10⁶; 0°C–2.95×10⁷. HBr, 40°C–2.5×10⁸; 30°C–7.5×10⁸; 25°C–1.32×10⁹; 20°C–2.37×10⁹; 10°C–8.10×10⁹; 0°C–3.0×10¹⁰. HI, 40°C–5.2×10⁸; 30°C–1.5×10⁹; 25°C–2.5×10⁹; 20°C–4.5×10⁹; 10°C–1.5×10¹⁰; 0°C–5.0×10¹⁰. Simple equilibrium models suggest that HNO₃, CH₃SO₃H and other acids up to 10x less soluble than HCl displace it from marine seasalt aerosols. HF is displaced preferentially to HCl by dissolved acidity at all relative humidities greater than about 80%, and should be entirely depleted in aged marine aerosols.  相似文献   

Vertical distribution of dimethylsulfide,sulfur dioxide,aerosol ions,and radon over the Northeast Pacific Ocean     

M. O. Andreae  H. Berresheim  T. W. Andreae  M. A. Kritz  T. S. Bates  J. T. Merrill 《Journal of Atmospheric Chemistry》1988,6(1-2):149-173

Dimethylsulfide (DMS), sulfur dioxide (SO₂), methanesulfonate (MSA), nonsea-salt sulfate (nss-SO₄ ^2–), sodium (Na⁺), ammonium (NH₄ ⁺), and nitrate (NO₃ ^–) were determined in samples collected by aircraft over the open ocean in postfrontal maritime air masses off the northwest coast of the United States (3–12 May 1985). Measurements of radon daughter concentrations and isentropic trajectory calculations suggested that these air masses had been over the Pacific for 4–8 days since leaving the Asian continent. The DMS and MSA profiles showed very similar structures, with typical concentrations of 0.3–1.2 and 0.25–0.31 nmol m^–3 (STP) respectively in the mixed layer, decreasing to 0.01–0.12 and 0.03–0.13 nmol m^–3 (STP) at 3.6 km. These low atmospheric DMS concentrations are consistent with low levels of DMS measured in the surface waters of the northeastern Pacific during the study period.The atmospheric SO₂ concentrations always increased with altitude from <0.16–0.25 to 0.44–1.31 nmol m^–3 (STP). The nonsea-salt sulfate (ns-SO₄ ^2–) concentrations decreased with altitude in the boundary layer and increased again in the free troposphere. These data suggest that, at least under the conditions prevailing during our flights, the production of SO₂ and nss-SO₄ ^2– from DMS oxidation was significant only within the boundary layer and that transport from Asia dominated the sulfur cycle in the free troposphere. The existence of a sea-salt inversion layer was reflected in the profiles of those aerosol components, e.g., Na⁺ and NO₃ ^–, which were predominantly present as coarse particles. Our results show that long-range transport at mid-tropospheric levels plays an important role in determining the chemical composition of the atmosphere even in apparently remote northern hemispheric regions.  相似文献   

东亚沙尘源区晴空和云上沙尘气溶胶特征   总被引：4，自引：4，他引：0  

茹建波  王天河  李积明  韩颖  张北斗 《中国沙漠》2018,38(2):372-383

利用2006年6月至2012年12月的CALIPSO Level 2 VFM产品、5 km分辨率的Aerosol Profile、Cloud Layer产品以及MISR反演的产品,揭示了东亚地区不同高度层上沙尘的时空分布特征,重点对比分析了东亚沙尘源区晴空和云上沙尘的垂直分布特征、消光系数和光学厚度。结果表明：塔克拉玛干沙漠和戈壁沙漠是东亚沙尘的主要源区,沙尘出现频率具有显著的季节差异,春季最多,夏秋相当,冬季最少,无论在晴空还是有云条件下,前者出现频率大于后者。对于同一地区而言,云上沙尘出现的最大高度较晴空沙尘更高。塔克拉玛干沙漠云上沙尘消光系数高值区集中在2~4 km,而戈壁沙漠则集中在3~5 km,但是在云层之上晴空和云上沙尘消光系数差别不大。塔克拉玛干沙漠以沙尘气溶胶为主,约占总气溶胶光学厚度的77%,晴空和云上沙尘光学厚度平均值分别为0.22和0.15;戈壁沙尘气溶胶约占总气溶胶光学厚度的52%,晴空和云上沙尘光学厚度的平均值分别为0.09和0.06。  相似文献   

实验室模拟研究大气二次有机气溶胶的形成   总被引：1，自引：0，他引：1  

徐永福  贾龙 《大气科学》2018,42(4):767-785

二次有机气溶胶（SOA）是大气中重要的气溶胶组分,主要由挥发性有机物（VOCs）经化学转化形成,对天气、气候、大气环境和人体健康有重要影响,但至今其确切的化学成分和形成机制还十分不清楚。研究SOA的方法主要采用实验室单个物种或多物种的化学过程的模拟研究,野外实际大气的SOA化学成分、源汇和多尺度分析的观测研究,以及大气中SOA形成的数值模拟的回报和预报研究。实验室研究是对SOA形成过程中获取基础数据和推究SOA生成机制的最主要手段。在过去的几十年中,特别是近五年,SOA的研究取得了较大的进展,其中包括SOA前体物、SOA形成机制及影响因子的进一步理解。本文就这些方面展开了概要性的综述,重点强调了我国研究人员所做的研究工作。在采用实验室烟雾箱系统模拟研究SOA方面,首先简述了烟雾系统的发展以及表征,讨论了跟烟雾箱箱体相关的壁效应问题,重点综述了萜烯类、芳香烃类、小分子类等化学物种转化形成SOA的研究进展。在采用流动管和其他反应器类模拟研究SOA方面,重点讨论了挥发性有机物在颗粒物表面或在液相中所形成的SOA的主要化学成分及其可能的作用。  相似文献   

基于MODIS数据的郑州市气溶胶时空变化特征分析     

李诺  刘战伟  卫林勇  林康聆  窦明 《气象与环境科学》2018,41(2):32-38

利用NASA发布的MODIS/Terra中Collection6数据集的MOD04_3K气溶胶光学厚度(AOD)产品,进行波段提取、重投影、剪裁等预处理,得到郑州市气溶胶光学厚度资料,对此进行统计分析,研究郑州市气溶胶光学厚度的时空变化特征。结果表明:1)2001-2016年郑州市AOD年均值整体以每年0.0033的速率增加,最大峰值出现在2011年(1.01),以2011年为界,2001-2011年呈显著增长趋势,2012-2016年呈显著下降趋势。AOD季节均值夏季的最大,春季的次之,冬季的最小。2)2001-2016年郑州市AOD夏季均值波动较大,春季均值与年均值趋势基本一致,AOD年均值和季均值与对应时间尺度的降水量有负相关关系。工业产值占GDP比重与AOD年均值呈正相关关系。3)2001-2016年郑州市AOD年均值空间分布呈现北高南低、东高西低的特征,高值区主要分布在新郑市、中牟县、郑州市区、荥阳市及巩义市的西北部。春、夏和秋季的AOD均值空间分布形态基本与年均值的分布一致,冬季的高值区集中在郑州市东南部(新郑市)。  相似文献   

Aerosol Optical Properties and Radiative Impacts in the Pearl River Delta Region of China during the Dry Season     

Boru MAI  Xuejiao DENG  Zhanqing LI  Jianjun LIU  Xiang'ao XIA  Huizheng CHE  Xia LIU  Fei LI  Yu ZOU  Maureen CRIBB 《大气科学进展》2018,35(2):195-208

Aerosol optical properties and direct radiative effects on surface irradiance were examined using seven years(2006–2012)of Cimel sunphotometer data collected at Panyu—the main atmospheric composition monitoring station in the Pearl River Delta(PRD) region of China. During the dry season(October to February), mean values of the aerosol optical depth(AOD)at 550 nm, the ?ngstr?m exponent, and the single scattering albedo at 440 nm(SSA) were 0.54, 1.33 and 0.87, respectively.About 90% of aerosols were dominated by fine-mode strongly absorbing particles. The size distribution was bimodal, with fine-mode particles dominating. The fine mode showed a peak at a radius of 0.12 μm in February and October(~0.10μm~3μm~(-2)). The mean diurnal shortwave direct radiative forcing at the surface, inside the atmosphere(FATM), and at the top of the atmosphere, was-33.4 ± 7.0, 26.1 ± 5.6 and-7.3 ± 2.7 W m~(-2), respectively. The corresponding mean values of aerosol direct shortwave radiative forcing per AOD were-60.0 ± 7.8, 47.3 ± 8.3 and-12.8 ± 3.1 W m~(-2), respectively. Moreover,during the study period, FATMshowed a significant decreasing trend(p 0.01) and SSA increased from 0.87 in 2006 to 0.91 in 2012, suggesting a decreasing trend of absorbing particles being released into the atmosphere. Optical properties and radiative impacts of the absorbing particles can be used to improve the accuracy of inversion algorithms for satellite-based aerosol retrievals in the PRD region and to better constrain the climate effect of aerosols in climate models.  相似文献