Anomalously strong North Atlantic jets, defined in this study as jets with wind speeds exceeding 100 m·s⁻¹, are notable due to their potential to induce high-impact weather. This study examines the kinematic processes that contribute to the intensification of anomalously strong North Atlantic jets, as well as the variability in those processes across a large number of events. Anomalously strong jets are objectively identified during September–May 1979–2018 within the Climate Forecast System Reanalysis and composited to reveal the synoptic-scale flow evolution associated with jet intensification. The analysis demonstrates that anomalously strong North Atlantic jets are most frequent during the winter compared with the fall and spring, and that their development is preceded by low-level warm-air advection, poleward moisture advection, and moist ascent within the warm conveyor belt of a surface cyclone beneath the equatorward jet-entrance region. A diagnosis of the irrotational and nondivergent components of the ageostrophic wind within the near-jet environment reveals that both wind components facilitate jet intensification via their nonnegligible contributions to negative potential vorticity (PV) advection and PV frontogenesis in the vicinity of the dynamic tropopause. Weather Research and Forecasting (WRF) model simulations of a jet event from December 2013 with and without latent heating further suggest that the ageostrophic wind field within the near-jet environment is substantially modulated by latent heating. The foregoing results indicate that a diagnosis of jet intensification during anomalously strong jet events is dependent on an accurate representation of the cumulative effects of latent heating within the near-jet environment.

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导致异常强烈的北大西洋急流增强的运动学过程

异常强劲的北大西洋喷气机，在本研究中定义为风速超过 100 m·s ^{-1 的}喷气机，由于它们有可能诱发高影响天气而引人注目。这项研究检查了导致异常强烈的北大西洋喷流增强的运动学过程，以及这些过程在大量事件中的变异性。在 1979 年 9 月至 2018 年 9 月至 2018 年期间，在气候预测系统再分析中客观地识别出异常强烈的急流，并进行合成以揭示与急流增强相关的天气尺度流动演变。分析表明，与秋季和春季相比，异常强烈的北大西洋急流在冬季最为频繁，并且在其发展之前是低层暖空气平流、极地湿气平流和温暖传送带内的湿上升。赤道急流入口区域下方的表面气旋。对近喷射环境中地转风的无旋和非发散分量的诊断表明，这两种风分量都通过它们对动态对流层顶附近的负势涡 (PV) 平流和 PV 锋生的不可忽视的贡献促进了喷射增强。2013 年 12 月有和没有潜热的急流事件的天气研究和预报 (WRF) 模型模拟进一步表明，近急流环境中的地转风场受到潜热的显着调节。上述结果表明，异常强射流事件期间射流增强的诊断取决于对近射流环境中潜热累积效应的准确表示。