A Frontal Identification System (FIS), initially designed to track Galernas in the Bay of Biscay, has been adapted to monitor cold fronts across Australia using wind shifts derived from ERA5 hourly reanalysis data. This high-resolution system tracks shallow, cloud-free fronts during the warm season, which can trigger bushfires, dust storms, extreme heat, and coastal weather extremes like Southerly Busters (SB) on the east coast. SB episodes, marked by sudden, squally south winds, pose hazards for boating and aviation. Our analysis of 35 SB events from 1994 to 2020 indicates that SBs originate from frontogenesis in Bass Strait (40 %) or from prefrontal troughs crossing the strait (60 %). Preceding synoptic conditions involve a Southern Ocean cold front driving cool maritime winds into the Australian thermal low, creating shallow convergence fronts (∼1000 m deep) facing warm continental winds. Onshore acceleration into the thermal low sharpens these new fronts (Type 2 fronts of the southern coast) and weakens the trailing primary ocean front, which may disappear due to high-pressure wave propagation, cold advection, and subsidence over the sea. These fronts can penetrate deep inland (Central Australian fronts) and initiate SBs on the southeast coast after interacting with the Great Dividing Range. All 35 SB events show active shallow front frontogenesis/frontolysis affecting the southern coast and inland regions. Upper-level reversed pressure gradients between the thermal low over the continent and the ocean depression maintain a wind shear region over the shallow inland cold advection. Intense warm north-westerlies south of the surface front, with wind speeds of 35–50 m s−1 between 700 and 550 hPa, contribute to mesofront formation preceding SB episodes. This jet also sustains strong cross-mountain winds over the Great Dividing Range, causing the lee trough at the coastal strip that precedes all SB episodes on the eastern coast. Understanding these dynamics can help predict and manage these events more effectively.

中文翻译：

---

揭示 Southerly Buster 事件期间澳大利亚浅层锋面的动态（1994-2020 年）


锋面识别系统 （FIS） 最初设计用于跟踪比斯开湾的 Galernas，现已用于使用从 ERA5 小时再分析数据得出的风向变化来监测澳大利亚各地的冷锋。这个高分辨率系统在温暖季节跟踪浅层、无云锋面，这可能会引发丛林大火、沙尘暴、极端高温和沿海极端天气，如东海岸的南风克星 （SB）。SB 事件以突然的狂风南风为标志，对划船和航空构成危险。我们对 1994 年至 2020 年的 35 次 SB 事件的分析表明，SB 起源于巴斯海峡的锋面发生 （40%） 或穿越海峡的前额槽 （60%）。前面的天气条件包括南大洋冷锋将凉爽的海风驱赶到澳大利亚热低压，形成面向温暖大陆风的浅辐合锋（∼1000 m 深）。陆上加速进入热低压使这些新的锋面（南部海岸的 2 型锋面）变得尖锐，并削弱了尾随的主要海洋锋面，这些主要洋锋可能会因高压波传播、冷平流和海上沉降而消失。这些锋面可以渗透到内陆深处（澳大利亚中部锋面），并在与大分水岭相互作用后在东南海岸启动 SB。所有 35 个 SB 事件都显示影响南部海岸和内陆地区的活跃浅锋锋发生/锋面溶解。大陆上空的热低压和海洋低气压之间的高层反向压力梯度在浅层内陆冷平流上保持了一个风切变区。地表锋以南强烈的暖西北风，风速为 35-50 m s-1，在 700 至 550 hPa 之间，有助于在 SB 事件之前形成中锋。 该急流还在大分水岭上维持着强大的跨山风，导致东海岸所有 SB 事件之前的沿海地带出现背风槽。了解这些动态有助于更有效地预测和管理这些事件。