冬季横断山区一次低空风切变诊断及模拟  

Diagnosis and Numerical Simulation of Low-level Wind Shear over the Hengduan Mountains in Winter

作　　者：任菊章[1] 杨雪 陶云[1] 付志嘉[3] 陈艳[1] 钟亚含 王曼[1] 金燕[4] Ren Juzhang;Yang Xue;Tao Yun;Fu Zhijia;Chen Yan;Zhong Yahan;Wang Man;Jin Yan(Yunnan Institute of Meteorological Sciences,Kunming 650034;Cangyuan Washan Airport of Yunnan Airport Group Co.,LTD.,Lincang 677400;Dali National Climate Observatory,Dali 671003;Yunnan Climate Center,Kunming 650034)

机构地区：[1]云南省气象科学研究所,昆明650034 [2]云南机场集团有限责任公司沧源佤山机场,临沧677400 [3]大理国家气候观象台,大理671003 [4]云南省气候中心,昆明650034

出　　处：《应用气象学报》2025年第1期77-89,共13页Journal of Applied Meteorological Science

基　　金：云南省科技厅重点研发计划——社会发展专项(202203AC100006);国家自然科学基金项目(42375043,42465004)。

摘　　要：沧源佤山机场位于横断山区得龙山,冬季飞机在起飞着陆过程中易遭遇低空风切变,造成复飞。应用机场气象站资料、自动气象站和风廓线雷达加密观测资料等,诊断分析了2021年12月29日沧源佤山机场区域出现的一次低空风切变复飞事件。结果表明:冬季一般天气条件下,横断山区盛行偏西南气流,沧源佤山机场东侧坝区存在小尺度局地山谷风环流。午后盛行风加强,机场地面转为一致的西南风,风速增加并超过5.0 m·s^(-1)后,机场东侧坝区谷风风速增加,并伴有垂直上升运动。随着太阳辐射减弱,盛行风开始减弱,东侧坝区内转为山风环流。数值模拟结果也显示:午后盛行偏西南风增强,促使机场地面风速和影响东侧坝区的下坡气流加速,与谷风在机场东侧坝区辐合,产生上升气流,上下层动量交换加强,边界层垂直不稳定加强,产生低空风切变,造成复飞。因此,边界层盛行风与局地谷风环流间的相互作用是造成2021年12月29日佤山机场东侧坝区出现瞬时低空风切变的主要原因。Cangyuan Washan Airport,located at Delong Mountain in the Hengduan Mountains,is prone to low level wind shear during takeoff and landing in winter,which is of great harm to aviation safety,and aviation departments attach great importance to it.It is also a key problem in refined weather forecasting and early warning under complex terrain.Therefore,it is essential to examine changes in low-level wind circulation around the airport.Using NCEP/NCAR reanalysis data,airport weather station data,encrypted automatic weather station data and wind profile radar data,a low-level wind shear turn-around event at Cangyuan Wushan Airport on 29 December 2021,is diagnosed and analyzed by statistical and numerical simulation methods.Results indicate that during winter,the southwest airflow prevails in the Hengduan Mountains,and the surface wind speed is relatively low.The small-scale local valley wind circulation in the east of Cangyuan Washan Airport is obvious.During daytime,the prevailing valley wind blows from the valley toward the airport.At night,the mountain wind blows from the airport back to the valley.Additionally,a vertical downdraft predominates in the approach area.However,there is a consistent southwest breeze in the afternoon.When the wind speed increases to more than 5.0 m·s-1,the prevailing southwest wind will cross the mountain,and the cross-mountain air on the ground will converge with the increased valley wind in the approach area,resulting in instantaneous vertical upward movement and forming low-level wind shear.The rapid fluctuations in wind direction and speed near the ground in the dam area on the east side of the airport significantly affects aviation safety.With the weakening of the solar radiation,the prevailing wind and valley wind begins to weaken at night,and the mountain wind circulation shifts towards the dam area on the east side of the airport,resulting in an increase in vertical subsidence movements.Numerical simulation results confirm that under the action of solar radiation heating,the preva

关 键 词：低空风切变 过山气流 山谷风环流 数值模拟 

分 类 号：P45[天文地球—大气科学及气象学]