摘要
利用常规天气资料、跑道自动观测(以下简称AWOS)资料、AMDAR等资料,对乌鲁木齐2010年12月19—20日出现的空中和地面东南风对飞行造成较为严重的风切变天气进行了分析,并尝试利用风廓线雷达资料分析空中东南风分布、下传、跑道垂直风切变的演变,分析认为:(1)乌鲁木齐机场地面东南大风多出现在春秋季,冬季多出现在中低空,而此次东南大风在12月出现在地面,比较少见。东南大风是在建立稳定的南高北低地面气压场下出现的,在起风前和大风持续期间,环流形势具有典型南冷北暖的特征。(2)AWOS资料表明:东南风过程中两次东南风阵性明显,同一时刻跑道两端出现了风向和风速的不连续,在跑道上形成较强的水平风切变。(3)风廓线资料显示:起风前空中2 000 m以下有东南风下传的作用,并具有阵性明显的特征,空中和地面出现东南风时,垂直方向上出现了风向和风速的不连续,有的时次风切变强度达到或超过中度。(4)具有较高时空分辨率的AMDAR资料,可以监测东南风下传的过程、垂直方向上风切变的变化、东南风层的高度和厚度以及阵性明显的特征,风廓线和AMDAR资料的共同使用可以更真实的反映中、低空风场的结构和演变,为风切变预报提供依据。
On December 19 to 20, 2010, low-level wind shear which caused by southeast wind occurred at Urumqi airport. The conventional weather data, runway automatic weather observation data （AWOS）, AMDAR data and other information were used to analyze the low-level southeast wind distribution, downward motion, variation in the vertical wind shear runway. The result shows： （1） the southeast wind at Urumqi airport occurred in winter is rarely. Southeast wind always appears when a higher surface pressure was established at the south than the north. Before and in the windy duration, it was colder at the south field than the north. （2）AWOS data showedthat the wind direction and speed appeared discontinuously in the same time at both ends of the runway and then strong horizontal wind shear occurred above the runway. （3）wind profiler radar data indicated the effect of momentum transported downwardly as the southeast wind blowed toward the ground below 2000 meters . which lead to vertical wind shear at moderate intensity or above.（4）because AMDAR data had higher spatial and temporal resolution, we can use it to monitor the process of momentum transport downward, and the southeast wind layer＇s height and thickness. Integrated use of wind profiler radar and AMDAR data can reflect the mid and low-level wind structure and evolution to provide a basis for forecasting wind shear.
出处
《沙漠与绿洲气象》
2012年第6期45-50,共6页
Desert and Oasis Meteorology
