The Formation of Barrier Winds East of the Loess Plateau and Their Effects on Dispersion Conditions in the North China Plains
The Formation of Barrier Winds East of the Loess Plateau and Their Effects on Dispersion Conditions in the North China Plains
复制标题
黄土高原以东障壁风的形成及其对华北平原扩散条件的影响
DOI：
10.1007/s10546-016-0159-4
复制
发表时间：
2016-10-01
影响因子：
4.3
通讯作者：
Fuentes, Jose D.
中科院分区：
文献类型：
--
作者：
Hu, Xiao-Ming;Li, Xingliang;Fuentes, Jose D.
黄土高原以东的华北平原是世界上污染最严重的地区之一。西部地区的弱地面气流加剧了该地区的空气污染。低空气流接近黄土高原时的减速，以及与大城市相关的粗糙度增强，以前被认为是NCP低风速的原因。通过单层弥散模式的数值模拟，我们发现黄土高原对气流的动态改变（不仅仅是由于山地阻塞而导致的简单减速）在降低NCP上空的风速中起着重要作用。动力诱导的偏北障风叠加在盛行的偏南/偏东南气流上，使高原以东50 ~ 100公里范围内的风速降低，部分解释了西北大平原西部的弱风。弱水平风造成的分散条件差可能导致污染物在该地区积聚。
The North China Plain (NCP) to the east of the Loess Plateau is one of the most heavily polluted areas in the world. Weak surface flow in the western part of the NCP exacerbates the air pollution in this region. Deceleration of low-level flow when approaching the Loess Plateau, together with enhanced roughness associated with large cities, were previously ascribed as the causes for low wind speeds in the NCP. Using numerical simulations with a one-layer dispersion model, we identify that dynamic modification of airflow by the Loess Plateau (not just simple deceleration due to mountain blocking) plays an important role in reducing the wind speed over the NCP. Dynamically-induced northerly barrier winds, superimposed on the prevailing southerly/south-easterly flow, reduce the wind speed in a 50–100 km wide region to the east of the Plateau, partially explaining the weak winds in the western part of the NCP. Poor dispersion conditions due to weak horizontal winds likely contribute to the accumulation of pollutants in this region.