Contrasting characteristics of the surface energy balance between the urban and rural areas of Beijing   总被引：1，自引：0，他引：1  

Linlin Wang  Zhiqiu Gao  Shiguang Miao  Xiaofeng Guo  Ting Sun  Maofeng Liu  Dan Li 《大气科学进展》2015,32(4):505-514

A direct comparison of urban and rural surface energy balances, as well as a variety of other variables including incoming shortwave/longwave radiation and aerosol optical depth, is conducted for the Beijing metropolitan area. The results indicate that, overall, the urban area receives a smaller amount of incoming shortwave radiation but a larger amount of incoming longwave radiation. However, comparisons in the aerosol optical depth and cloud fraction at the two locations suggest that neither aerosol optical depth nor cloud fraction alone can explain the difference in the incoming shortwave radiation. The urban–rural differences in the incoming longwave radiation are unlikely to be caused by the presence of more abundant greenhouse gases over the urban area, as suggested by some previous studies, given that water vapor is the most dominant greenhouse gas and precipitable water is found to be less in urban areas. The higher incoming longwave radiation observed over the urban area is mostly likely due to the higher temperatures of the ambient air. The urban area is also found to always produce higher sensible heat fluxes and lower latent heat fluxes in the growing season. Furthermore, the urban area is associated with a larger amount of available energy(the sum of sensible and latent heat fluxes) than the rural area, except in May and October when evapotranspiration in the rural area significantly exceeds that in the urban area. This study provides observational evidence of urban–rural contrasts in relevant energy-balance components that plausibly arise from urban–rural differences in atmospheric and land-surface conditions.  相似文献   

Analysis and evaluation of the global aerosol optical properties simulated by an online aerosol-coupled non-hydrostatic icosahedral atmospheric model     

DAI Tie  SHI Guangyu  Teruyuki NAKAJIMA 《大气科学进展》2015,32(6):743-758

Aerosol optical properties are simulated using the Spectral Radiation Transport Model for Aerosol Species(SPRINTARS)coupled with the Non-hydrostatic ICosahedral Atmospheric Model(NICAM). The 3-year global mean all-sky aerosol optical thickness(AOT) at 550 nm, the ngstr m Exponent(AE) based on AOTs at 440 and 870 nm, and the single scattering albedo(SSA) at 550 nm are estimated at 0.123, 0.657 and 0.944, respectively. For each aerosol species, the mean AOT is within the range of the Aero Com models. Both the modeled all-sky and clear-sky results are compared with observations from the Moderate Resolution Imaging Spectroradiometer(MODIS) and the Aerosol Robotic Network(AERONET). The simulated spatiotemporal distributions of all-sky AOTs can generally reproduce the MODIS retrievals, and the correlation and model skill can be slightly improved using the clear-sky results over most land regions. The differences between clear-sky and all-sky AOTs are larger over polluted regions. Compared with observations from AERONET, the modeled and observed all-sky AOTs and AEs are generally in reasonable agreement, whereas the SSA variation is not well captured. Although the spatiotemporal distributions of all-sky and clear-sky results are similar, the clear-sky results are generally better correlated with the observations. The clear-sky AOT and SSA are generally lower than the all-sky results, especially in those regions where the aerosol chemical composition is contributed to mostly by sulfate aerosol. The modeled clear-sky AE is larger than the all-sky AE over those regions dominated by hydrophilic aerosol, while the opposite is found over regions dominated by hydrophobic aerosol.  相似文献   

南极长城站地区1987年夏季大气气溶胶研究          下载免费PDF全文

朱光华  汪新福  沈新尹  吴瑜光  赵俊琳  任燕  王丽平  刘培桐  李果 《极地研究》1990,2(2):44-50

1987年1～2月用分八级的串列撞击式采样器在南极长城站地区进行了三次大气气溶胶采样,用质子激发X荧光分析法进行了元素质量浓度测定,获得了18种元素质量浓度的粒径分布谱。计算了气溶胶中各种粒径各元素浓度对于地壳中含量和盐度为35.0‰海水中含量的富集因子。对气溶胶中粗粒子、细粒子和超细粒子的特征进行了讨论并对它们的来源作了推测。  相似文献   

PRELIMINARY STUDY OF VARIATION OF SO₂ AND AEROSOL PARTICLE BACKGROUND CONCENTRATIONS IN THE EASTERN CHINA          下载免费PDF全文

Luo Chao  Ding Guo''an  Yang Dongzhen  Tang jie  Zhou Xiuji 《Acta Meteorologica Sinica》1994,8(3):263-269

The average concentrations of sulphur dioxide,sulfate aerosol and TSP were about 8-10 ppb,15.08 μg m^-3,and 241.40 μg m^-3 respectively,which were measured at the Lin'an regional background station during August-November,1991.The higher concentrations of SO₂ and SO₄^2- maybe acidify the rainfall.It has a great influence upon the human health and ecosystem.The simulated results indicate that the distributions of SO₂ and SO₄^2- were determined by local emission sources.Average aerosol particle number density was 2.0×10⁴ cm^-3.It shows that social development and human activities strongly affect the atmospheric background level.  相似文献   

The interpretation of baseline atmospheric turbidity measurements at Cape Grim,Tasmania     

C. M. R. Platt  G. R. Patterson 《Journal of Atmospheric Chemistry》1986,4(1):187-197

Five years of turbidity data at Cape Grim have been analysed. The turbidity at 500 nm in clean maritime airmasses from the South to the West shows a seasonal variation, with a minimum in winter. There is also a variation in turbidity with wind speed. The winter minimum can be explained partially by a minimum in wind strength in that season. On the assumption, based on observations at Cape Grim and at other locations, that the boundary layer turbidity is caused by seasalt haze, an attempt is made to interpret the observed turbidity values and their seasonal changes. Optical extinction coefficients at the surface deduced from the measured values of optical depth are compared with extinction coefficients calculated from Mie theory using particle size distributions measured at Cape Grim. Reasonable agreement is obtained when the growth of salt particles in the high maritime humidity is considered, using both theoretical models and previous experimental results together with the rapid increase in salt concentration with wind speed.  相似文献   

Sulfate and methanesulfonate in the maritime aerosol at Cape Grim,Tasmania     

G. P. Ayers  J. P. Ivey  H. S. Goodman 《Journal of Atmospheric Chemistry》1986,4(1):173-185

High-volume aerosol filters, exposed in maritime air masses at Cape Grim since late 1976, were analysed for excess sulfate (not of seasalt origin) and methanesulfonate. The mean concentrations (standard errors) of 2.80(0.59) and 0.176(0.027) nmole/m³ respectively are about half those reported in a recent study of aerosol samples from various locations in the Atlantic and Pacific oceans.Methanesulfonate concentration varied seasonally by at least an order of magnitude with a summer maximum and winter minimum. No comparable cycle was found for excess sulfate.  相似文献   

泽当、景洪大气气溶胶粒子的物理、化学特性   总被引：9，自引：1，他引：9  

杨军  朱彬  李子华 《气象学报》2001,59(6):795-802

利用 1 997～ 1 999年在西藏泽当、云南景洪观测地飞得到的大气气溶胶资料 ,分析了气溶胶粒子的物理化学特性 ,包括质量浓度、数浓度、光学吸收系数和化学组成 ,初步讨论了有关的影响因子 ,并同国内外其它地区的观测结果进行了比较。结果表明 ,大气气溶胶粒子在以上两地以及与其它地区之间存在明显的差异  相似文献   

贺兰山地区春季沙尘气溶胶质量浓度的观测分析   总被引：41，自引：4，他引：41  

牛生杰  孙继明  陈跃  刘宏杰 《高原气象》2001,20(1):82-87

通过对贺兰山地区大气背景、浮尘、扬沙和沙尘暴天气的采样，得到在不同天气条件下的气溶胶质量浓度，而且在它们之间存在一定的倍数关系。由Anderson和KB－120E采样器得到的总浓度是有差异的。  相似文献   

塔里木盆地区域沙尘气溶胶特征分析     

高卫东  魏文寿 《山地学报》2002,20(3):354-359

沙尘天气是塔里木盆地区常见的天气现象，对大气沙尘气溶胶的分析表明，沙尘暴期间，沙尘气溶胶浓度远大于非尘暴期间。对策勒和阿克苏两地的比较分析表明，由于两地地理环境的差异，沙尘暴期间，策勒站细颗粒质量百分比呈下降趋势；阿克苏站细颗粒质量百分比呈上升趋势，说明尘暴间由于当地沙尘源丰富，细粒物质较多，细粒物质迅速被携带于高空，成为沙尘气溶胶的主要来源。阿克苏站大气气溶胶颗粒主要来源于地表沙源。富集因子分析表明，阿克苏站和策勒站沙尘暴和扬尘天气的各地壳元素含量均高于浮尘和背景大气，而且能见度能见度愈小，高出的比例愈大；各种沙尘天气发生时，均以亲地元素的浓度为最高。  相似文献   

华东地区大气本底条件下大气透明度的变化特点   总被引：1，自引：0，他引：1  

洪盛茂 《气象》1996,22(9):10-14

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