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101.
Evolution of aerosol vertical distribution during particulate pollution events in Shanghai
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A set of micro pulse lidar(MPL)systems operating at 532 nm was used for ground-based observation of aerosols in Shanghai in 2011.Three typical particulate pollution events(e.g.,haze)were examined to determine the evolution of aerosol vertical distribution and the planetary boundary layer(PBL)during these pollution episodes.The aerosol vertical extinction coefficient(VEC)at any given measured altitude was prominently larger during haze periods than that before or after the associated event.Aerosols originating from various source regions exerted forcing to some extent on aerosol loading and vertical layering,leading to different aerosol vertical distribution structures.Aerosol VECs were always maximized near the surface owing to the potential influence of local pollutant emissions.Several peaks in aerosol VECs were found at altitudes above 1 km during the dust-and bioburning-influenced haze events.Aerosol VECs decreased with increasing altitude during the local-polluted haze event,with a single maximum in the surface atmosphere.PM2.5 increased slowly while PBL and visibility decreased gradually in the early stages of haze events;subsequently,PM2.5 accumulated and was exacerbated until serious pollution bursts occurred in the middle and later stages.The results reveal that aerosols from different sources impact aerosol vertical distributions in the atmosphere and that the relationship between PBL and pollutant loadings may play an important role in the formation of pollution. 相似文献
102.
Recent glacial retreat in High Asia in China and its impact on water resource in Northwest China 总被引:48,自引:0,他引:48
YAO Tandong WANG Youqing LIU Shiying PU Jianchen SHEN Yongping & LU Anxin .Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China .Cold Arid Regions Environmental Engineering Research Institute Chinese Academy of Sciences Lanzhou China 《中国科学D辑(英文版)》2004,47(12):1065-1075
There are about 46298 glaciers in the High Asiain China, the total glacial area is about 59406 km , andtotal glacial volume about 5590 km3. These glaciersmainly concentrate around the Himalayas Mountains,Nyainqentanglha Mountains, Kunlun Mountains,Karakoram Mountains and Tianshan Mountains. Theglaciers in the Tibetan Plateau are the major compo-nent of the glaciers in the High Asia in China. Theseglaciers extend north to the arid and desert regions,and become the main water resource in … 相似文献
103.
CHEN Weifeng CHEN Peirong XU Xisheng & ZHANG Min The State Key Laboratory of Mineral Deposit Research Department of Earth Sciences Nanjing University Nanjing China 《中国科学D辑(英文版)》2005,48(12):2104-2117
The South China, including Yangzi Craton and the Cathaysian Block, belongs to the southern part of East Asia continent. It borders Pacific plate on the east side and Qinling-Dabie Orogen on the north side. During the middle-late Cretaceous, a number of downfaulted red basins (the terrestrial sedimentary basins in Fig. 1) and volcanic- sedimentary basins had been developed in South China[1,2], in which the con-temporaneous basaltic rocks were generally distributed (Fig. 1). Although the … 相似文献
104.
Influencing domain of peripheral sources in the urban heavy pollution process of Beijing 总被引:1,自引:0,他引:1
Multiple cities in a diveloped economic area may consist of a city cluster,and the difusion and mixing of its pollutants result in the effect of pollutants plume between cities and the large-scale regional pollution diffusion phenomenon.The distant transfer and diffusion of pollutants occurs when massive aerosols are affected by the dynamic porcess of large-scale circulations.Research suggesten that the life span of aerosol particles whose diameters are about 1 um is the longest.The longevity … 相似文献
105.
A 3-D convective cloud model with compressible non-hydrostatic dynamics and the spectral bin microphysics of a 2-D slab-symmetric
model has been used to simulate an observed supercell storm occurring on 29 June, 2000 near Bird City, Kansas, USA. The main
objective of this paper is to study the evolution of particles in this convective storm with bin spectral microphysics scheme.
Graupels form and grow through two mechanisms, deposition and riming, with the riming process dominant on top of the inflow
and in the upper portion of main updraft. Over the outflow and during the developing and mature stages of the storm, graupel
particles mainly grow through deposition with dominant unimodal spectra. Most fall out after growing up. Reducing initial
relative humidity disturbance (increasing initial potential temperature disturbance) has negative impact on the formation
and growth of graupels over the inflow (outflow). This study shows that large graupel and hail could be suppressed by altering
the deposition and coalescence process over the inflow and main updraft. At different locations of the convective cells and
with different initial humidity and potential temperature disturbance, the graupel formation and growth mechanisms are different,
so as to the feasible hail suppression locations and methods.
Supported by National Natural Science Foundation of China (Grant Nos. 40537034, 40805057), and Foundation of Key Laboratory
of Meteorological Disaster of Ministry of Education in Nanjing University of Information Science & Technology (Grant No. KLME060202) 相似文献
106.
Mafic granulite xenoliths have been discovered in many volcanoes (especially alkali basalt and kimberlite) all over the world. They formed generally in lower crust, and recorded lots of in- formation on the lithosphere formation and crust-mantle interacti… 相似文献
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