Spatio-temporal variations and potential diffusion characteristics of dust aerosol originating from Central Asia
源于中亚的气溶胶潜在扩散特征及时空变化
中亚地处干旱和半干旱气候区,是全球沙尘气溶胶贡献度较大的区域。利用中分辨率成像光谱仪（Moderate-resolution Imaging Spectrometer, MODIS）和云—气溶胶偏振雷达（Cloud-Aerosol Lidar with Orthogonal Polarization, CALIOP）遥感数据,从宏观角度对2002-2015年中亚地区气溶胶光学厚度（Aerosol Optical Depth, AOD）时空分布特征及沙尘气溶胶光学特性垂直分布特征进行分析,利用拉格朗日混合型的扩散模型（Hybrid Single Particle Lagrangian Integrated Trajectory, HYSPLIT）讨论沙尘运输的季节性变化。结果表明：① 中亚AOD空间分布呈现显著的季节性差异,四季均值春（0.412）>夏（0.258）>冬（0.167）>秋（0.159）,14年间呈现增加趋势;② 中亚AOD高值区域主要集中于咸海地区和新疆的塔里木盆地,其中,咸海地区AOD年均值为0.278,年均增幅为3.175%,主要受咸海退化所导致的干涸湖底裸露面积加大的影响;塔克拉玛干沙漠地区AOD年均值为0.421,年均增幅0.062%,主要受温度和风速两方面的影响,不同季节下主导因素略有差异;③ 尘源区气溶胶主要集中在近地面0~2 km范围内,沙漠上空气溶胶退偏比范围（10%45%）略大于咸海上空（15%30%）;咸海地区色比值（0.30.8）小于沙漠地区（0.50.9）,且在0~2 km和4~6 km有两个高频色比值分别为0.5和0.3,说明相比沙尘气溶胶,咸海地区的盐尘气溶胶球形程度较高,颗粒更小,飘散高度更高;④ 咸海地区盐尘潜在扩散方向主要以东北,西南和南为主,向东北方向的扩散距离最远,影响范围可达俄罗斯中部地区,西南方向扩散路径高度和距离较近,主要影响乌兹别克斯坦和土库曼斯坦,但发生比例相对较高,塔克拉玛干沙漠地区起尘后大部分沙尘颗粒仍沉降在尘源区附近,向东部地区扩散的沙尘气溶胶,主要影响中国青海、甘肃、宁夏、陕西等地区。
Central Asia is located in arid and semi-arid regions. This region contributes to dust aerosols because of desertification and land degradation. In order to better understand temporal variability, vertical distribution, and potential diffusion characteristics of salt dust and desert dust in Central Asia, we studied the intranasal changes in dust aerosol from the Aral Sea basin and Taklimakan Desert using MODIS aerosol data and CALIOP data, and analyzed its potential seasonal diffusion from 2005 to 2015 using the HYSPLIT model.
中亚位于干旱和半干旱区域。由于沙漠化和土地退化导致气溶胶。为了更好地的理解中亚气溶胶的时间变率、垂直分布和盐尘和沙尘的潜在扩散特征。我们使用MODIS气溶胶数据和CALL OP数据研究了从咸海流域到塔克拉玛干沙漠内部变化，使用HYSPLIT模型了来分析2005到2015年它的潜在季节性扩散。
Results showed that AOD of this region was high in spring and summer and low in autumn and winter. Over the 14 years, it showed an increasing trend. The mean values of the four seasons were: spring (0.412) > summer (0.258) > autumn (0.167) ≈ winter (0.159).
The annual AOD high value areas were mainly concentrated in the Tarim Basin in southern Xinjiang and surrounding areas of Aral Sea. The annual average value of AOD in Aral Sea was 0.278, and annual amplification was 3.175%.
结果显示该区域的AOD在春季和夏季是高值，在秋季和冬季是低值。在14年间，AOD呈现出增加的趋势。四季的均值：春（0.412）>夏（0.258）>秋(0.167)≈冬（0.159）。每年的AOD高值区主要集中在新疆南部的塔里木盆地和咸海周围。咸海AOD均值为0.278.每年的扩散率3.175%。
It is indicated that the degradation of the Aral Sea had a direct impact on the AOD surrounding area. The annual average value of AOD in the Tarim Basin was 0.421, and annual amplification was 0.062%, which was mainly affected by temperature and wind speed, and the dominant factors were slightly different in different seasons.
它表明咸海的土地退化对周边区域AOD有直接影响。塔里木盆地的均值为0.421，每年扩散率0.062%，主要受温度、风速。主要影响因素在不同的季节有细微的不同。
Dust aerosols were mainly concentrated in a range of 0-2 km. Aerosol depolarization ratio range in the desert (10%-45%) was slightly greater than that in the Aral Sea (15%-30%) and the aerosol color ratio range in the Aral Sea (0.3-0.8) was less than that of the desert (0.5-0.9).
There were two high-frequency color ratios of 0.5 and 0.3 from the dust zone over 0-2 km and 4-6 km of salt dust.
Compared to dust aerosols, salt dust aerosols had smaller irregularities and particle size, and higher impact of height range.
气溶胶主要集中在0-2公里范围内。沙漠的气溶胶去极化率范围（10%-45%）比咸海（15%-30%）较高。咸海气溶胶色度范围（0.3-0.8)比沙漠(0.5-0.9)要低。两个高频率色度0.5和0.3来自沙尘区0-2公里和4-6公里烦人沙尘。与气溶胶相比，盐尘气溶胶更小的不规则度和粒径，更高的高范围的影响。
As for the Aral Sea region, the potential distance and height of air parcel trajectories to the northeast were greater than to the west and south, whereas the air parcel trajectory proportion of the former was lower than that of the latter, which mainly affect Uzbekistan and Turkmenistan.
Most of the dust in the Taklimakan Desert is still settling in the vicinity of the dust source region. The potential diffusion path to the eastern regions has impact on Qinghai, Gansu, Ningxia, Shaanxi and other regions.
至于咸海区域，潜在的距离和大气轨迹的高度向东北比西部和南部大，大气运动轨迹先前的低于之后的面积，主要影响乌兹别克斯坦和土库曼斯坦。塔克拉马干沙漠许多沙尘仍然在沙源附近。潜在扩散路径向东扩散，对青海、甘肃、宁夏、陕西和其他区域有影响。
