Dataset for "Microburst Detection with the WRF Model: Effective Resolution and Forecasting Indices"

Abstract: Microbursts are meteorological phenomena in the lower troposphere which can produce damaging surface winds and pose a severe risk to aircraft flying close to the ground. As these events usually span less than 4 km and 15 min, the spatiotemporal resolution is a challenge for numerical simulations. Although research of microburst using operative mesoscale models is scarce, the Weather Research and Forecasting model has been used in the diagnosis of this phenomenon. In this paper, such model is used to simulate several microburst conducive days using two different boundary conditions. The energy spectra of the simulations are computed to evaluate the effective resolution of the model. The results are in line with previous studies and produce no notable differences among the boundary conditions. Nonetheless, the energy spectra show an over-energetic troposphere at microscale resolutions, rendering the effective resolution inadequate for microburst forecasting using the simulated physics variables. Thus, mesoscale indices are analysed as a prognostic tool. The Wind Index, the Wet Microburst Severity Index and the Microburst Windspeed Potential Index do not show high forecasting performances, even though improving the results of climatology. Also, notable differences among the boundary conditions can be seen. The most consistent results are achieved by the Wet Microburst Severity Index. Note: Due to the high resolution used, the 40 simulations produced are over 7 TB is size. Only the WRF configuration files are provided here, to reproduce the simulations if necessary. The NCL scripts can be used to plot the Energy Spectra and several variables used in the evaluation. The R scripts can be used to plot ROC curves. See each file description for further detail.摘要：微下击暴流（Microbursts）是对流层低层的气象现象，可产生破坏性地面大风，对近地飞行的航空器构成严重威胁。由于此类事件的空间尺度通常小于4公里、持续时长不足15分钟，其时空分辨率对数值模拟（numerical simulations）而言是一项挑战。尽管针对微下击暴流的中尺度模式（mesoscale models）相关研究较为匮乏，但天气研究与预报模式（Weather Research and Forecasting model）已被用于该现象的诊断分析。本文采用该模式，通过两种不同的边界条件（boundary conditions）对多个利于微下击暴流发生的日数开展模拟试验。研究人员计算了模拟结果的能谱（energy spectra），以评估模式的有效分辨率。结果与既往研究结论一致，且不同边界条件间未出现显著差异。不过，能谱结果显示，在微尺度分辨率下对流层存在能量过剩的情况，导致基于模拟物理变量开展微下击暴流预报时，模式的有效分辨率无法满足需求。因此，本文对中尺度指数作为预报工具（prognostic tool）展开分析。风指数（Wind Index）、湿微下击暴流强度指数（Wet Microburst Severity Index）以及微下击暴流风速潜力指数（Microburst Windspeed Potential Index）即便相较于气候态基准结果有所提升，也未表现出优异的预报性能。此外，不同边界条件间可观测到显著差异。其中，湿微下击暴流强度指数的预报结果最为稳定。注意：由于本次模拟采用了较高的分辨率，本次生成的40组模拟文件总容量超过7 TB。本文仅提供WRF模式配置文件，以便在需要时复现模拟过程。可使用NCL脚本（NCL scripts）绘制能谱及评估所用的多个变量；可使用R脚本（R scripts）绘制ROC曲线（Receiver Operating Characteristic curve）。详细信息请参阅各文件的说明文档。