发表机构
Department of Science and Technology - Philippine Atmospheric, Geophysical, and Astronomical Services Administration; Project Severe Weather Archive of the Philippines（科学与技术部-菲律宾大气、地球物理和天文服务管理局; 菲律宾严重天气档案项目）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究基于菲律宾1186份龙卷与水龙卷报告及ERA5探空数据，构建了群岛首份此类强天气的基准气候学，发现其环境特征与中纬度不同，需采用局部阈值而非中纬度校准参数预测。
AI 中文摘要
龙卷现象在每个有人居住的大陆都有记录，但用于预测龙卷的环境条件主要是基于中纬度记录开发和验证的，热带地区在很大程度上未被研究。本研究收集了菲律宾从20世纪初到2025年的1186份龙卷与水龙卷报告，并为每份报告匹配了ERA5邻近探空数据，构建了该群岛这类强天气事件的首份基准气候学及环境特征。活动集中在三个走廊，大多被山脉环绕，每个主要岛群各有一个，且在5-10月窗口内呈现明显的阶段性，与雷暴频率的年周期密切相关。这些环境在热力学上是可形成龙卷的，但在动力学上较浅：平均对流有效位能超过了美国大平原的典型值，而0-6公里层的整体风差保持在10节以下，与中纬度地区不稳定度和风切变共同增加的协方差不同。几乎所有的判别方差都集中在最低1公里处，其中68%-79%的近地面水平涡度是顺流的，在最有组织的廓线中达到96%，且 hodograph（风暴相对风廓线）保留了低层曲率。因此，复合指数即使在龙卷频发时也会低估，需要采用局部重新缩放的阈值，这意味着中纬度校准的对流参数可能会对热带海洋型环境做出错误诊断。
英文摘要
Tornadoes are documented on every inhabited continent, yet the environmental conditions used to anticipate them were developed and validated overwhelmingly on mid-latitude records, leaving tropical regimes largely unexamined. Here, we collected 1,186 combined tornado and waterspout reports in the Philippines spanning the early 1900s to 2025 and paired each with an ERA5 proximity sounding to construct the first baseline climatology and environmental characterization of these events in the archipelago. Activity concentrates in three corridors, mostly flanked by mountain ranges, one in each major island group, and is sharply phased within a May-October window that closely tracks the annual cycle of thunderstorm frequency, peaking in August and lagging into October for waterspouts alongside the tropical cyclone season. These events cluster in the mid-to-late afternoon, consistent with a daytime heating regime rather than nocturnal convection. The environments are thermodynamically permissive but kinematically shallow, with convective available potential energy (CAPE) exceeding typical Great Plains values, while the 0-6 km bulk wind difference (BWD; DLS) remains weak at $\sim$10-14 kt, departing from the mid-latitude covariance in which instability and shear increase together. Although streamwise vorticity is modest in magnitude, nearly all discriminating variance resides in the lowest kilometer, where 68-79% of near-surface horizontal vorticity is streamwise, reaching $>$0.005 s$^{-1}$ and 96% streamwiseness in the most organized profiles, and the hodographs retain low-level curvature. Consequently, composite indices remain low even as tornadoes and waterspouts recur. Mid-latitude-calibrated parameters can therefore misdiagnose tropical-maritime regimes, and recalibration toward shallow-layer, orientation-aware kinematic discriminators may recover the diagnostic signal.
Comments21 pages, 7 figures, 1 table. Submitted to a journal. Final part of Project Severe Weather Archive of the Philippines (SWAP)
