Observation of nocturnal low-level wind shear and particulate matter in urban Beijing using a Doppler wind lidar
Observation of nocturnal low-level wind shear and particulate matter in urban Beijing using a Doppler wind lidar
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DOI：
10.1080/16742834.2017.1368349
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发表时间：
2017-08
影响因子：
2.3
通讯作者：
Yong Chen;Junling An;Jian Lin;Yele Sun;Xiquan Wang;Zifa Wang;Jing Duan
中科院分区：
文献类型：
--
作者：
Yong Chen;Junling An;Jian Lin;Yele Sun;Xiquan Wang;Zifa Wang;Jing Duan
摘要利用移动多普勒测风激光雷达和固定风塔，在北京城区5个观测点进行了弱天气强迫下夜间山风和相应颗粒物（PM）演变的野外试验。在北京南北20 km范围内的两个观测点，在距地面40-320 m处出现明显的风切变和水平风零区，延迟时间为1.5 h。北京北部城区低空急流的风速和高度大于东部城区。240 m低空PM的平均水平分布与夜间地面PM的平均水平分布相似。PM2.5（空气动力学直径≤2.5 μm）的累积中心在北风急流到来之前没有随风向的改变而发生突变。
Abstract A field experiment of nocturnal mountain wind and corresponding particulate matter (PM) evolution under weak synoptic forcing at five sites within urban Beijing was conducted using a moving Doppler wind lidar and a fixed tower. Clear wind shear and zero-horizontal-wind zones at 40–320 m above the ground with a delay of 1.5 h were found at two sites between 20 km from north to south urban Beijing. The wind speed and height of the low-level jet at the north urban Beijing site were greater than those at the east urban Beijing site. The average horizontal distribution of low-level PM at 240 m was similar to the ground-level PM at night. The PM2.5 (aerodynamic diameter ≤2.5 μm) accumulation center showed no abrupt changes with a shift in wind direction until the northerly wind jet arrived.