Aerosol chemical, physical, and radiative characteristics near a desert source region of northwest China during ACE‐Asia
Aerosol chemical, physical, and radiative characteristics near a desert source region of northwest China during ACE‐Asia
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DOI：
10.1029/2003jd004239
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发表时间：
2004-10
影响因子：
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通讯作者：
Jin Xu;M. Bergin;R. Greenwald;J. Schauer;M. Shafer;J. Jaffrezo;G. Aymoz
中科院分区：
文献类型：
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作者：
Jin Xu;M. Bergin;R. Greenwald;J. Schauer;M. Shafer;J. Jaffrezo;G. Aymoz
在树干和固体颗粒中，混合高度的日变化以及上午的局部燃烧源和下午的粉尘源都是造成这种现象的原因。观测到了两组不同的气溶胶质量散射效率ESCAT2.5，一组是以沙漠沙尘为主的气溶胶(�1.0m 2g�1)，另一组是以本地污染物为主的气溶胶(�3.0m 2g�1)。在实地研究期间，有三次重大的沙尘事件，平均一次发生几天。最显著的沙尘暴导致24小时平均PM2.5浓度(空气动力学直径小于2.5毫米的粒子的质量浓度)为453mgm�3，4月8日的峰值为2510 mm�1。沙尘暴期间PM2.5的平均质量浓度约为169mgm�3，比本地污染期间观测到的44mgm�3的平均值高出约4倍。当当地污染是细颗粒物的主要来源时，有机质(OM)是主要的化学成分，占PM2.5质量的41%，其次是地壳物质(29%)、硫酸盐(17%)和元素碳(EC)(13%)。在沙尘暴期间，�占PM2.5质量的51%是地壳物质，其次是�(11%)和OM(9.5%)。元素的富集系数表明，燃煤、生物质燃烧和移动源排放是当地重要的污染源。总体而言，我们的结果表明，除了沙尘外，局部污染对该地区的气溶胶性质也有显著影响。索引词：0305大气组成和结构：气溶胶和颗粒物(0345,4801)；0345大气组成和结构：污染-城市和区域(0305)；0360大气组成和结构：辐射的传输和散射；9320与地理区域有关的信息：亚洲；关键词：气溶胶，沙尘，ACE-亚洲
in both sap and ssp, resulting from diurnal changes in the mixing height as well as from local combustion sources in the morning and dust sources in the afternoon. Two distinct populations of aerosol mass scattering efficiencies Escat_2.5, one for aerosols dominated by desert dust (� 1.0 m 2 g � 1 ) and the other for aerosols composed primarily of local pollutants (� 3.0 m 2 g � 1 ), are observed. During the field study there were three significant dust events that occurred for, on average, several days at a time. The most significant dust storm resulted in a 24-hour-average PM2.5 concentration (mass concentration of particles having aerodynamic diameters less than 2.5 mm) of 453 m gm � 3 and a peak ssp of 2510 Mm � 1 on 8 April. The mean PM2.5 mass concentration during the dust storm periods is approximately 169 m gm � 3 , about 4 times greater than the mean value of 44 m gm � 3 observed during local pollution periods. When local pollution is the dominant source of fine particulate mass, organic matter (OM) is the major chemical component, contributing 41% to the PM2.5 mass, followed by crustal material (29%), sulfate (17%), and elemental carbon (EC) (13%). During sand storm periods, � 51% of PM2.5 mass is crustal material, followed by CO3� (11%) and OM (9.5%). The element enrichment factors indicate that coal combustion, biomass burning, and mobile source emissions are important local pollution sources. Overall, our results indicate that in addition to dust, local pollution also has a significant influence on aerosol properties in the region. INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 0360 Atmospheric Composition and Structure: Transmission and scattering of radiation; 9320 Information Related to Geographic Region: Asia; KEYWORDS: aerosol, dust, ACE-Asia