大气污染扩散的高斯烟羽模型及其GIS集成研究

以VB6结合SuperMap Objects 5.2为开发平台,实现高斯烟羽模型与GIS的集成,可视化地表达大气污染物的扩散过程,并通过实例讨论了GIS与烟羽模型集成的方法、技术流程及其他相关问题.     

大气气溶胶中痕量金属元素的研究进展

综述了近年来国内外学者对大气气溶胶中痕量金属元素的研究进展,介绍了痕量金属元素的地球化学行为,以及大气气溶胶中痕量金属的源解析方法、在环境中的循环与污染、生物有效性及对人体的健康效应。建议研发更可靠的分析方法或在线检测仪器,避免采样和样品前处理过程中痕量金属的污染和损失;建立监测网络,形成区域性的大气监测模式,更全面地分析污染来源;与监测超级站建设、空气污染流行病学设计和毒性机制研究相结合,建立更加完善的研究体系。     

灰霾天气期间南京气溶胶的化学组成及光学特性研究

利用2013年6月—12月灰霾天气期间南京城郊气溶胶采样结果,研究气溶胶中水溶性离子的特征和相关性;结合同期城区的大气成分逐时观测资料,分析黑碳的日变化及其与气态污染物的关系;运用光学参量计算模型(OPAC)和辐射传输模型(TUV)研究气溶胶的光学特性及辐射强迫。结果表明:发生灰霾天气时南京城郊主要大气污染物是细颗粒,其中SO2-4与NO-3是最主要的水溶性无机盐离子,NO-3/SO2-4质量比较高,呈现硫酸盐和硝酸盐混合型污染特征。黑碳浓度具有明显的日变化特征,呈双峰型结构。灰霾期间硫酸盐气溶胶在大气层顶和地面造成的平均辐射强迫分别为-10.6 W/m2和-10.8 W/m2,黑碳气溶胶在正午大气层顶和地面造成的平均辐射强迫分别为9.12 W/m2和-29.77 W/m2。     

Development of a new aerosol monitoring system and its application in Fukushima nuclear accident related aerosol radioactivity measurement at the CTBT radionuclide station in Sidney of Canada

A high volume aerosol sampler ("Grey Owl") has been designed and developed at the Radiation Protection Bureau, Health Canada. Its design guidance is based on the need for a low operational cost and reliable sampler to provide daily aerosol monitoring samples that can be used as reference samples for radiological studies. It has been developed to provide a constant air flow rate at low pressure drops (∼3 kPa for a day sampling) with variations of less than ±1% of the full scale flow rate. Its energy consumption is only about 1.5 kW for a filter sampling over 22,000 standard cubic meter of air. It has been demonstrated in this Fukushima nuclear accident related aerosol radioactivity monitoring study at Sidney station, B.C. that the sampler is robust and reliable. The results provided by the new monitoring system have been used to support decision-making in Canada during an emergency response.     

Performance of data acceptance criteria over 50 months from an automatic real-time environmental radiation surveillance network

The automatic real-time environmental radiation surveillance network of Catalonia (Spain) comprises two subnetworks; one with 9 aerosol monitors and the other with 8 Geiger monitors together with 2 water monitors located in the Ebre river. Since September 2006, several improvements were implemented in order to get better quality and quantity of data, allowing a more accurate data analysis. However, several causes (natural causes, equipment failure, artificial external causes and incidents in nuclear power plants) may produce radiological measured values mismatched with the own station background, whether spurious without significance or true radiological values. Thus, data analysis for a 50-month period was made and allowed to establish an easily implementable statistical criterion to find those values that require special attention. This criterion proved a very useful tool for creating a properly debugged database and to give a quick response to equipment failures or possible radiological incidents. This paper presents the results obtained from the criterion application, including the figures for the expected, raw and debugged data, percentages of missing data grouped by causes and radiological measurements from the networks. Finally, based on the discussed information, recommendations for the improvement of the network are identified to obtain better radiological information and analysis capabilities.     

Analysis of surface and aerosol polarized reflectance for aerosol retrievals from polarized remote sensing in PRD urban region

A precise estimate of polarization induced by surface is crucial for polarized remote sensing dedicated to monitoring aerosol properties over urban area. The accurate knowledge of interaction between surface and aerosol polarized reflectance is essential for accurately achieving aerosol properties. In order to study surface and aerosol polarized reflectance for aerosol retrievals over urban area, a new airborne directional polarimetric camera (DPC) with high spatial resolution (4 m at 4000 m a.g.l) was developed. The surface polarized reflectance over distinct surface covers of urban area (forest, shrub, and soil) were studied using DPC measurements during a field campaign in the Pearl River Delta (PRD), China. The large variations were found in surface polarized reflectance of distinct urban covers due to surface type variability. For all surface types, the empirical BPDF model cannot describe accurately surface polarized reflectance at all possible illumination and observation geometries. From the quantitatively study of relationship between surface and aerosol polarized contribution to DPC measurements, we show that the polarized contributions of aerosol, which optical properties were defined by ground-based measurements, are much larger than the polarized contribution of surface, and found that the polarized contribution of surface covers increases with decreasing NDVI. The effect of polarization accuracy of measurements on aerosol retrieval was also investigated using DPC measurements, and found that 0.1% polarization accuracy of measurements can be neglected when AOD is retrieved using polarized measurements. Based on the information of effects of polarized reflectance differences between distinct surface covers and polarization accuracy of polarized measurements on retrieved aerosols over urban area, we found that the accuracy of aerosol retrieval over forest covers is higher than other surface types using polarized remote sensing.     

排烟冷却塔烟气抬升高度的计算分析

华北地区某电厂排烟冷却塔烟气抬升高度的光学照相法实测结果显示,选用S／P模式计算出排烟冷却塔烟气括升高度是合理的。在环境风速小、空气潮湿条件下,采用排烟冷却塔排放方式有利于污染物稀释扩散;在环境风速大、空气干燥、逆温等不利气象条件时,采用排烟冷却塔排放方式,烟气抬升高度较低。     

热诱导浮力羽流涡旋结构直接数值模拟

涡旋结构是湍流流场重要的研究内容之一,也是影响特殊火行为的重要因素之一,如涡旋在飞火传播中起着非常重要的作用。火羽流涡旋结构的详细分析对火灾蔓延特性的研究有重要指导意义。该文对轴对称热羽流和平面热羽流进行了直接数值模拟,分别基于涡旋动力学及涡旋稳定性角度对计算结果进行详细分析。研究表明平面热羽流的涡量值明显高于轴对称热羽流,平面热羽流具有较低的脉动频率。从涡量输运方程出发,分析得出拉伸项的存在降低了轴对称热羽流的混合强度。     

Regional differences of column-related aerosol parameters in Germany

With the development of satellite experiments supplementary and validating ground-based measurements are gaining growing importance for the inference and evaluation of radiation-related aerosol parameters. Both kinds of measurements have been conducted and interpreted mainly under globally or locally restricted aspects for a limited time period only. Results are presented from four rural regions (coastal zone, lowlands, highlands, high mountain); they are column-related aerosol parameters, deduced from monitoring programs of spectral aerosol optical depth (AOD) as well as almucantar sky irradiance measurements. After 13 years of continuous measurements of trends and variations in aerosol optical depths, these results are based on 5 years of data collection (1994–1998). There are significant differences among the parameters of the four regions when related to the inversion method of the AOD spectra. A clear interdependence was found between all column-related parameters and the real part of the refractive index, which in turn depends on the chosen retrieval method. The differences among the four regions are characterized mainly by their different altitudes, with relative humidity being responsible for their internal variation. An increase in the relative humidity from 35 to 55–60% influences the most interesting parameters such as refractive index (real part), hemispheric backscattered fraction b, and direct radiative forcing ΔF as follows: The real part of the refractive index decreases from 1.6±0.05 to 1.42±0.04, b decreases by 8–10%, and, due to the increase in AOD, ΔF increases by about 20% in the spectral region 0.4–1.0 μm. The quantities of the parameters depend on the retrieval methods too.     

确定大气环境承载力的烟云足迹法

本文讨论了大气承载力的定义,同时也给出了计算大气承载力的烟云足迹法的原理和计算公式,此外还给出了根据区域气象条件计算烟云足迹函数的具体算式和大气环境承载力的计算实例,烟云足迹分析法可为区域间的排污权交易提供技术基础.