地理学报 ›› 2017, Vol. 72 ›› Issue (3): 507-520.doi: 10.11821/dlxb201703011

• 土地利用与环境变化 • 上一篇    下一篇

中亚沙尘气溶胶时空分布特征及潜在扩散特性分析

张喆1,2(), 丁建丽1,2(), 王瑾杰1,2,3   

  1. 1. 新疆大学资源与环境科学学院,乌鲁木齐 830046
    2. 绿洲生态教育部重点实验室,乌鲁木齐 830046
    3. 新疆交通职业技术学院,乌鲁木齐 831401
  • 收稿日期:2016-07-07 修回日期:2016-10-15 出版日期:2017-03-15 发布日期:2017-05-03
  • 作者简介:

    作者简介:张喆(1988-), 女, 新疆石河子人, 博士生, 主要从事干旱区资源环境遥感研究。E-mail: zhangzhe_0110@yeah.net

  • 基金资助:
    自治区重点实验室专项基金(2016D03001, 2014KL005);自治区科技支疆项目(201591101);国家自然科学基金项目(U1303381, 41261090, 41161063);自治区专家顾问团决策研究与咨询项目(201601044);新疆大学优秀博士研究生创新项目(XJUBSCX-2014012)

Spatio-temporal variations and potential diffusion characteristicsof dust aerosol originating from Central Asia

Zhe ZHANG1,2(), Jianli DING1,2(), Jinjie WANG1,2,3   

  1. 1. College of Resources and Environment Science, Urumqi 830046, China
    2. China Key Laboratory of Oasis Ecosystem of Education Ministry, Xinjiang University, Urumqi 830046, China
    3. Xingjiang Vocational andTechnical College of Communication, Urumqi 831401, China
  • Received:2016-07-07 Revised:2016-10-15 Online:2017-03-15 Published:2017-05-03
  • Supported by:
    Xinjiang Uygur Autonomous Region Key Laboratory Special Fund, No.2016D03001, No.2014KL005;Xinjiang Uygur Autonomous Region Science and Technology Support Project, No.201591101;National Natural Science Foundation of China, No.U1303381,No.41261090, No.41161063;Decision Making Research and Consulting Project of the Expert Advisory Group of the Autonomous Region, No.201601044;Innovation Project of Doctoral Candidate of Xinjiang University, No.XJUBSCX-2014012

摘要:

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(0.3~0.8)小于沙漠地区(0.5~0.9),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。

关键词: 气溶胶, 时空分布, 潜在扩散路径, 中亚

Abstract:

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. 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%. 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. 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. 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.

Key words: aerosol, spatial and temporal characteristics, potential diffusion, Central Asia