School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea.
Sci Total Environ. 2010 Mar 1;408(7):1707-18. doi: 10.1016/j.scitotenv.2009.12.018. Epub 2010 Jan 8.
In this study, we investigate the transport of dust particles, its vertical distribution, and the associated meteorological conditions during an Asian dust event that was observed in Seoul, Korea on May 29-31, 2008. This study analyzes data from ground-based and space-borne 2-wavelength polarization lidars, particulate mass concentrations, and synoptic weather data. Surface meteorological station observations of dust phenomena, dust transport model, and weather maps consistently show that the dust particles were transported from the source regions (Inner Mongolia, Man-Ju, and Ordos areas) to Korea via the northeastern part of China. Network observations of the PM(10) concentrations in Korea revealed that a majority of the heavy dust particles traveled across South Korea from the northwest to the southeast direction with a horizontal scale of 250-300km and a traveling speed of approximately 40kmh(-1). This extraordinary dust event, in terms of its intensity and timing during the year, occurred due to the blockage of an unusually intensified low-pressure system in the northeastern part of China as well as high-pressure system centered over the Sea of Okhotsk and the Kuril Islands. The low values of the particle depolarization ratio (delta(532)) (<or=0.05) and color ratio (CR) during the pre-dust period indicate the presence of spherical, non-dust, and relatively small particles. The mean delta(532) value was approximately 0.123+/-0.069 between altitudes of ground approximately 2.8km, and 0.161+/-0.049 for near-surface dust layer (ground approximately 1.2km). This value is quite similar to that obtained during the 3-year SNU-Lidar measurements in Seoul (delta(532) approximately 0.136+/-0.027). The value of delta(532) during the 2nd multilayered dust episode ranged between 0.081 and 0.120 for near-surface dust layers, and between 0.076 and 0.114 for elevated dust layers. The CALIPSO measurements of beta(532), delta(532), and CR also revealed the presence of dense dust aerosols along the transport route.
在这项研究中，我们研究了 2008 年 5 月 29 日至 31 日在韩国首尔观测到的亚洲沙尘暴事件期间尘埃颗粒的传输、垂直分布和相关气象条件。本研究分析了地面和星载双波长偏振激光雷达、颗粒质量浓度和天气综合数据。地面气象站观测到的沙尘现象、沙尘输送模式和天气图一致表明，沙尘颗粒是通过中国东北部从源区（内蒙古、满洲里和鄂尔多斯地区）输送到韩国的。韩国对 PM(10)浓度的网络观测显示，大多数重尘颗粒以大约 40kmh(-1)的速度从西北向东南方向穿越韩国，水平尺度为 250-300km。就其强度和一年中的时间而言，这次非同寻常的沙尘事件是由于中国东北部异常加强的低气压系统以及鄂霍次克海和千岛群岛上空的高气压系统的阻塞造成的。在沙尘前期间，粒子退偏比（delta(532)）（<or=0.05）和颜色比（CR）的低值表明存在球形、非沙尘和相对较小的颗粒。在地面约 2.8km 高度之间，平均 delta(532)值约为 0.123+/-0.069，在近地面沙尘层（地面约 1.2km）中约为 0.161+/-0.049。这与首尔 SNU-Lidar 三年测量中获得的值（delta(532)约 0.136+/-0.027）非常相似。第二次多层沙尘事件期间，近地面沙尘层的 delta(532)值在 0.081 到 0.120 之间，高空沙尘层的 delta(532)值在 0.076 到 0.114 之间。CALIPSO 对 beta(532)、delta(532)和 CR 的测量也揭示了在传输路径上存在密集的沙尘气溶胶。
