Temporal variations in PM10 and particle size distribution during Asian dust storms in Inner Mongolia
Temporal variations in PM10 and particle size distribution during Asian dust storms in Inner Mongolia
复制标题
DOI：
10.1016/j.atmosenv.2008.08.014
复制
发表时间：
2008-11-01
影响因子：
5
通讯作者：
Li, Yong
中科院分区：
文献类型：
--
作者：
Hoffmann, Carsten;Funk, Roger;Li, Yong
在中国内蒙古锡林郭勒草原，大气粉尘浓度增加可以分为两种类型，即本地和超区域类型的基础上，灰尘的来源。而本地类型的特点是由粉尘排放，超区域类型的沙尘天气导致高粉尘通道和沉积速率。在沙尘天气过程中，PM（10）和PM（1）浓度的时间变化，颗粒尺寸分布和摩擦速度u。使用Laser Dust Monitor（由GRIMM Aerosol GmbH制造）以5分钟间隔测量。局部起尘的临界摩擦速度u。(t)测得的当地土壤来源的粉尘浓度在0.6m s（-1）以上。通过MWAC捕集器收集总悬浮颗粒（TSP），并通过激光粒度仪（Analysette 22，Fritsch GmbH）测量。TSP的平均D[4/3]颗粒直径为23.0 μ m，测得的最大颗粒的尺寸高达100 μ m。虽然PM（10）类别的细粉尘占TSP质量的58%至63%，但较粗的颗粒（> 30 μ m）约占TSP质量的四分之一。在一些强沙尘暴结束时，即使风速已经减缓，沙尘浓度仍然保持在较高的水平。低于0.3 m s（-1）。这些阶段的特点是大于60 μ m的尘埃颗粒的高沉积速率。(c)2008爱思唯尔有限公司保留所有权利。
Two types of increased atmospheric dust concentration could be distinguished in the Xilingele grassland in the Chinese Province of Inner Mongolia, based on the dust origin i.e. local versus supra-regional type. While the local type is characterized by dust emission, dust events of the supra-regional type cause high dust passages and deposition rates. During dust events the temporal variability of the PM(10)- and PM(1)-concentrations, the particle size distribution and the friction velocity u. were measured in 5 min intervals using a Laser Dust Monitor (by GRIMM Aerosol GmbH). The threshold friction velocity for local dust emission u.(t), at which dust of local soils origin was measured, was above 0.6 m s(-1). The total suspended particles (TSP) was collected by MWAC catchers and measured by a Laser Particle Sizer (Analysette 22 by Fritsch GmbH). The average D[4/3] particle diameter of the TSP was 23.0 mu m and the greatest particles measured had sizes of up to 100 mu m. While fine dust of the PM(10) category contained between 58% and 63% of the TSP-mass, coarser particles (> 30 mu m) contributed to about a fourth of the TSP-mass. At the end of some strong dust storms, the dust concentrations remained at a high level even though wind speeds had already slowed down and u. was below 0.3 m s(-1). These phases were characterized by high deposition rates for dust particles greater than 60 mu m. (c) 2008 Elsevier Ltd. All rights reserved.