Wind profiler observations of a sting jet
Wind profiler observations of a sting jet
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风廓线仪对刺射流的观测
DOI：
10.1002/qj.398
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发表时间：
2009
影响因子：
8.9
通讯作者：
P. Clark
中科院分区：
文献类型：
--
作者：
G. Parton;G. Vaughan;E. Norton;K. Browning;P. Clark
在中纬度气旋风暴中，一些最具破坏性的地表风被归因于一种被称为刺流的现象。以前的研究已经推断出刺喷流是如何从它们的对流层中部起源发展起来的，但是还没有直接观测到对流层中部的这些风特征。在2002年10月27日的珍妮特风暴期间，风暴云头的尖端经过了位于威尔士阿伯里斯特威斯的甚高频风廓线仪，使得能够以高的空间和时间分辨率测量刺式喷流的结构。这些观测结果显示，刺式急流区域存在多个倾斜结构，在云头经过高空后，风的两个尾部持续增加。英国气象局统一模型（UM）的模拟显示，倾斜结构遵循θw表面，并且在经过英国时，刺式射流沿着θ表面下降，在下降过程中加速和干燥。观测到的结构的水平和垂直尺度是兼容的倾斜对流释放条件对称不稳定的云头。在英格兰东部的卡丁顿，一架超高频风廓线仪对刺式喷流进行了进一步观测，当时刺式喷流已经与围绕风暴循环的冷传送带合并。在卡丁顿最低公里的不稳定的温度分布，使破坏性的强风阵风被带到表面的对流羽流，但是，这种强烈的垂直混合没有正确地表示在UM。版权所有© 2009皇家气象学会
Some of the most damaging surface winds experienced in midlatitude cyclonic storms have been attributed to a phenomenon known as a sting jet. Previous studies have deduced how sting jets develop from their midtropospheric origin, but there have been no direct observations of these wind features in the midtroposphere. During Windstorm Jeanette on 27 October 2002, the tip of the storm's cloud head passed over a VHF wind profiler at Aberystwyth, Wales, allowing the structure of a sting jet to be measured with high spatial and temporal resolution. These observations showed a multiple slantwise structure to the sting jet region, with two tails of increased winds that persisted after the passing of the cloud head aloft. Simulations by the Met Office Unified Model (UM) showed that the slantwise structure followed θw surfaces, and that the sting jet descended along θ surfaces as it passed over the UK, accelerating and drying during its descent. The horizontal and vertical scales of the observed structures are compatible with slantwise convection releasing conditional symmetric instability within the cloud head. Further observations of the sting jet were obtained by a UHF wind profiler at Cardington in Eastern England, where the sting jet had merged with the cold conveyor belt circulating around the storm. An unstable temperature profile in the lowest kilometre over Cardington enabled damaging gusts of strong winds to be brought to the surface in convective plumes; however, this strong vertical mixing was not represented correctly in the UM. Copyright © 2009 Royal Meteorological Society