Identification of dust sources and hotspots in East Asia during 2000–2015: implications for numerical modeling and forecasting
Identification of dust sources and hotspots in East Asia during 2000–2015: implications for numerical modeling and forecasting
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DOI：
10.5194/acp-2016-681
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发表时间：
2016-10
影响因子：
6.3
通讯作者：
Xuelei Zhang;D. Tong;Guangjian Wu;Xin Wang;A. Xiu;Yongxiang Han;Tianli Xu;Shichun Zhang;Hongmei Zhao
中科院分区：
文献类型：
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作者：
Xuelei Zhang;D. Tong;Guangjian Wu;Xin Wang;A. Xiu;Yongxiang Han;Tianli Xu;Shichun Zhang;Hongmei Zhao
抽象的。更详细地了解东亚沙尘事件特征和沙源的近期变化可以有效改进区域沙尘模拟和预报。在此，我们重新评估了以往对东亚沙尘暴变化趋势预测的准确性，并根据2000年至2015年的卫星观测建立了相对详细的沙尘事件清单。收集和分析了东亚地区462个沙尘暴事件的2000多幅中分辨率成像光谱辐射仪（MODIS）图像，通过彩色RGB图像、亮温差和轨迹模拟相结合，对单个事件进行了溯源。 HYSPLIT 模型。春季沙尘事件频率减少，但夏季和秋季频率增加。在已查明的沙尘排放源中，沙地和湖床是主要沙尘源，而不是沙石荒漠。东亚沙尘热点主要是干涸的湖床、河床和冲积扇。最近与人类活动（采矿和过度开采水资源）相关的土地利用变化被认为是导致沙尘源区域扩大的主要因素之一，特别是在塔克拉玛干沙漠的东北部。轨迹分析还表明，沙尘甚至可以通过蒙古气旋向北输送，到达远东地区甚至北极圈，潜在影响北极地区的气候和生态系统。最近在尘埃模型中采用的基于物理的动态方法减少了尘埃建模中对经验源函数的依赖；然而，将这些计划缩小到区域规模的有效性需要用此处报告的“真实情况”信息进一步验证。
Abstract. More detailed knowledge regarding recent variations in the characteristics of East Asian dust events and dust sources can effectively improve regional dust modeling and forecasts. Here we reassess the accuracy of previous predictions of trends in dust variations in East Asia, and establish a relatively detailed inventory of dust events based on satellite observations from 2000 to 2015. More than 2000 Moderate Resolution Imaging Spectroradiometer (MODIS) images of 462 sand and dust storm events over East Asia were collected and analyzed, and individual events were tracked back to their sources through a combination of color RGB images, brightness temperature difference, and trajectory simulations using the HYSPLIT model. Decreased dust event frequency in spring but increased frequencies in summer and autumn were observed. Of the identified dust emission sources, sandy lands and lake beds, rather than the sandy and stone deserts, were found to be the dominant dust sources. Dust hotspots in East Asia are mainly dry lake and river beds and alluvial fans. Recent changes in land use associated with anthropogenic activities (mining and excessive exploitation of water resources) are revealed as one of the major factors leading to an expansion of dust source regions, especially for the northeastern part of Taklimakan desert. Trajectory analysis also shows that dust can even be transported northwards by the Mongolia Cyclone, to the Far East region and even the Arctic Circle, potentially affecting the climate and ecosystem of the Arctic region. Recent physically-based dynamic approaches adopted in dust models reduce the reliance on empirical source functions in dust modeling; however, the validity of down-scaling these schemes to regional scale needs to be further verified with "ground-truth" information as reported here.