Summertime trans‐Pacific transport of Asian dust
Summertime trans‐Pacific transport of Asian dust
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DOI：
10.1029/2010gl043995
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发表时间：
2010-09
影响因子：
5.2
通讯作者：
K. Yumimoto;K. Eguchi;I. Uno;T. Takemura;Z. Liu;A. Shimizu;N. Sugimoto;K. Strawbridge
中科院分区：
文献类型：
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作者：
K. Yumimoto;K. Eguchi;I. Uno;T. Takemura;Z. Liu;A. Shimizu;N. Sugimoto;K. Strawbridge
2009年8月中旬，太平洋盆地两侧的地面激光雷达网络探测到了上升的尘埃层。地面激光雷达、空间激光雷达CALIOP和数值模型的联合分析表明，塔克拉玛干沙漠排放的尘埃颗粒在12至13天内横跨太平洋。这是夏季来自塔克拉玛干沙漠的亚洲沙尘跨太平洋运输的第一个证据。8月12-16日，塔克拉玛干沙漠发生了一次大范围沙尘暴，原因是地面风大，冷锋伴生。许多尘埃颗粒被周围陡峭的山坡形成的上坡风提升到自由大气中。这一喷尘过程类似于春季的情况。然后，塔克拉玛干沙尘在海拔6-8公里的地方向东输送。这种高的输送高度使得塔克拉玛干尘埃可以被输送到太平洋以外的地方，而不受夏季太平洋高压向东南外流的影响。2009年8月中旬500hPa风场异常显示，在110-140°E和180-140°W附近，受东南-西北向气压梯度的驱动，西北风增强，表明沙尘事件期间的气压形势有利于跨太平洋输送。
In mid‐August 2009, ground‐based lidar networks on both sides of the Pacific Basin detected an elevated dust layer. A combined analysis by ground‐based lidars, space‐borne lidar CALIOP, and numerical models revealed that dust particles emitted in the Taklimakan Desert were transported across the Pacific Ocean in 12 to 13 days. This was the first evidence of summertime trans‐Pacific transport of Asian dust from the Taklimakan Desert. A large‐scale dust storm occurred in the Taklimakan Desert during 12–16 August due to a strong surface wind accompanied by a cold front. Many dust particles were lifted up into the free atmosphere by the upslope wind formed by the steep slope of the surrounding mountains. This dust injection process was analogous to that for springtime cases. The Taklimakan dust was then transported eastward at 6–8 km altitude. This high transport altitude allowed the Taklimakan Dust to be transported beyond the Pacific Ocean without the effect of the southeasterly outflow of the summertime Pacific high. The wind field anomaly at 500 hPa in mid‐August 2009 shows increases of northwesterly winds driven by SE–NW pressure gradients around 110–140°E and 180–140°W, indicating that the pressure pattern during the dust event favored the trans‐Pacific transport.