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Atmospheric Rivers intensify extreme precipitation and flooding across Australia 大气河流加剧了澳大利亚各地的极端降水和洪水

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-10-08 DOI: 10.1016/j.wace.2025.100812

Sucheta Pradhan , Conrad Wasko , Murray C. Peel

Atmospheric rivers (ARs) are narrow corridors of intense water vapor transport in the atmosphere. While the link between atmospheric rivers and extreme precipitation has been established across many regions of the world, the relationship between atmospheric rivers and flooding, the ultimate hazard resulting from extreme precipitation, remains poorly understood. Utilizing 467 Hydrologic Reference Stations (HRS) across Australia, the contribution of ARs to extreme precipitation and flooding is investigated by calculating the probability of occurrence of an AR on peak over threshold (POT) event days using different lag periods. By examining the tail behaviour of heavy precipitation and flooding caused by ARs, using the Generalized Pareto distribution (GPD), the magnitude to which ARs impact extreme events, and how this varies with event severity, is also quantified. Here, we find that southeast Australia has the highest AR concurrence (around 75–100 %) with extreme precipitation and streamflow events. The median magnitude of extremes is 20–70 % higher in the presence of an AR. In addition, the return periods of extreme flood and precipitation events of a given magnitude are on average 2 to 12 times shorter when they coincide with an AR compared to when they do not coincide with an AR. Our study highlights that ARs are a major factor in significantly increasing the frequency of extreme weather events in different regions of Australia. This suggests a need to incorporate AR impacts in hydrological modelling to enable better water resource management and flood risk assessment.

大气河（ARs）是大气中密集水汽输送的狭窄通道。虽然在世界许多地区已经确立了大气河流与极端降水之间的联系，但对大气河流与洪水（极端降水造成的最终危害）之间的关系仍然知之甚少。利用澳大利亚467个水文参考站（HRS），通过计算不同滞后期的峰值超过阈值（POT）事件日发生AR的概率，研究了AR对极端降水和洪水的贡献。通过使用广义帕累托分布（GPD）检查由ar引起的强降水和洪水的尾部行为，ar影响极端事件的程度以及随事件严重程度的变化也被量化。在这里，我们发现澳大利亚东南部与极端降水和河流事件的AR发生率最高（约75 - 100%）。极端事件的中位数强度在AR存在时要高出20 - 70%。此外，当极端洪水和降水事件与AR同时发生时，其重现周期平均比不与AR同时发生时短2 - 12倍。我们的研究强调，AR是显著增加澳大利亚不同地区极端天气事件频率的主要因素。这表明有必要将AR影响纳入水文模型，以便更好地进行水资源管理和洪水风险评估。

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引用次数: 0

Impacts of climate change on extreme weather indices in Ecuadorian cities: A socioeconomic analysis 气候变化对厄瓜多尔城市极端天气指数的影响：社会经济分析

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-10-07 DOI: 10.1016/j.wace.2025.100810

Diego Portalanza , Malena Torres-Ulloa , Eduardo Alava , Jussen Facuy , Cristian Zuluaga , Rina Bucaram , Angelica Durigon , Simone Ferraz

Climate change poses a significant threat to Ecuador, a nation characterized by diverse climates and geographical features. This study investigates the impacts of climate change on extreme weather events and socioeconomic variables across nine key Ecuadorian cities using the RegCM4 regional climate model and the Global Gridded Relative Deprivation Index (GRDI). The analysis includes historical trends and future projections under RCP2.6 and RCP8.5 scenarios for three extreme climatic indices: Consecutive Dry Days (CDD), Cold Nights (TN10p), and Warm Spell Duration Indicator (WSDI). Our findings indicate a consistent increase in CDD and WSDI, with significant decreases in TN10p across all cities over the past four decades, which are projected to continue under future climate scenarios. A Random Forest model was employed to explore the socio-economic impacts by predicting future changes in GRDI, highlighting how urban and rural deprivation might evolve in response to climatic changes. The results underscore the need for targeted adaptation strategies to address the unique vulnerabilities of each city and emphasize the critical role of land-use and land-cover changes (LULCC) in mitigating climate change impacts. This study provides essential insights for policymakers and stakeholders, emphasizing the urgency of integrating climate resilience into urban development to ensure sustainable futures for urban centers in Ecuador.

气候变化对厄瓜多尔这个气候和地理特征多样的国家构成了重大威胁。本研究利用RegCM4区域气候模式和全球网格化相对剥夺指数（GRDI）研究了气候变化对厄瓜多尔9个主要城市极端天气事件和社会经济变量的影响。分析了RCP2.6和RCP8.5情景下连续干旱日（CDD）、寒夜（TN10p）和暖期持续时间指标（WSDI） 3个极端气候指标的历史趋势和未来预测。我们的研究结果表明，在过去40年里，所有城市的CDD和WSDI持续增加，TN10p显著减少，预计在未来的气候情景下，这一趋势将继续下去。采用随机森林模型，通过预测GRDI的未来变化来探索社会经济影响，突出了城市和农村贫困如何随着气候变化而演变。研究结果强调了有针对性的适应战略的必要性，以解决每个城市独特的脆弱性，并强调了土地利用和土地覆盖变化（LULCC）在缓解气候变化影响中的关键作用。本研究为政策制定者和利益相关者提供了重要见解，强调了将气候适应能力纳入城市发展的紧迫性，以确保厄瓜多尔城市中心的可持续未来。

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引用次数: 0

Integrating non-stationarity and uncertainty in design life levels based on climatological time series 基于气候时间序列的设计寿命水平非平稳性和不确定性的综合

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-27 DOI: 10.1016/j.wace.2025.100807

Occitane Barbaux , Philippe Naveau , Nathalie Bertrand , Aurélien Ribes

This work focuses on inferring design life levels for extreme events under non-stationary conditions. Its objectives are twofold. The first one is to provide a single indicator that summarizes relevant and interpretable information about large values in time series, even when stationarity cannot be assumed. Classical risk indicators such as the 100-year return level become difficult to interpret in a non-stationary framework. To address this, we leverage the existing concept of the equivalent reliability (ER) level. Under stationarity, the ER level coincides with the classical return level, but it differs otherwise. More precisely, the ER level ensures that the probability of having all observations below the ER level during a specified design period is controlled. This definition ensures interpretability in terms of safety or failure risk. A second objective is to capture stochastic and estimation uncertainty, a key aspect in any risk analysis, as uncertainties due to inference schemes can grow with extreme intensities. We incorporate both by using the Bayesian predictive distribution. Although well known in Bayesian statistics, the predictive distribution has rarely been applied to climatological time series risk analysis.

Our approach is demonstrated on simulated data and on a case study of annual maxima of temperatures at a site in Southern France. To do so, a non-stationary Bayesian hierarchical extreme value model is used to combine data from 26 CMIP6 general circulation model simulations (SSP2-4.5, 1850-2100) with observations. The resulting predictive ER levels clearly indicate that non-stationarity over a design period of interest, as well as sampling and estimation uncertainty, have to be taken into account for risk assessment. For example, the 1000-year posterior predictive ER level for 2050-2100 is higher than any non-stationary 1000-year return level median estimate over the same period, reflecting the increasing risk due to the non-stationarity of the SSP 2-4.5 pathway.

这项工作的重点是推断非平稳条件下极端事件的设计寿命水平。它的目标是双重的。第一种方法是提供一个单一的指标，该指标总结了时间序列中大值的相关和可解释的信息，即使不能假设平稳性。经典的风险指标，如100年回报水平，在非平稳框架下变得难以解释。为了解决这个问题，我们利用了等效可靠性（ER）级别的现有概念。在平稳性条件下，ER水平与经典回归水平一致，反之则不同。更准确地说，ER水平确保在指定设计期间所有观测值低于ER水平的概率得到控制。这个定义确保了在安全或故障风险方面的可解释性。第二个目标是捕获随机和估计不确定性，这是任何风险分析中的一个关键方面，因为推理方案的不确定性可能会以极端强度增长。我们通过使用贝叶斯预测分布将两者结合起来。虽然在贝叶斯统计中很有名，但预测分布很少应用于气候时间序列风险分析。

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引用次数: 0

Projected impacts of climate and land use changes on streamflow extremes in the upper awash Basin, Ethiopia 气候和土地利用变化对埃塞俄比亚上冲盆地极端水流的预估影响

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-26 DOI: 10.1016/j.wace.2025.100806

Selamawit Haftu Gebresellase , Zhiyong Wu , Wada Idris Muhammad , Gebremedhin Gebremeskel Haile

This study examines the projected effects of climate and Land Use and Land Cover (LULC) changes on streamflow extremes in the Upper Awash Basin (UAB), Ethiopia. Using high-performing CMIP6 climate models under SSP4.5 and SSP8.5, and future LULC scenarios under Business-As-Usual (BAU) and Governance (GOV) for the 2030s and 2060s, the SWAT model was employed to simulate hydrological responses. Results revealed that climate change significantly affects streamflow extremes, with high-flow indices; Maximum High Flow (MHF), counts of High-Flow Pulses (HPC), and duration of High-Flow Pulses (HPD) showing pronounced increases, while low-flow indices; Minimum Low Flow (MLF), counts of low-flow pulses (LPC), and duration of low-flow pulses (LPD) exhibited substantial declines. For instance, under SSP8.5 in the 2060s, MHF, HPC, and HPD increased by 63.16 %, 26.85 %, and 14.96 %, respectively, whereas MLF, LPC, and LPD decreased by 67.11 %, 34.40 %, and 5.95 %. In contrast, LULC changes demonstrated statistically nonsignificant effects on both high- and low-flow indices across all scenarios and periods. The BAU scenario projected substantial urban and cropland expansion, resulting in decreased forest and shrubland areas, while the GOV scenario emphasized sustainable land management, controlling urban sprawl and increasing forest cover. Despite these differences, LULC-induced changes in streamflow extremes remained marginal compared to the overwhelming influence of climate change. This study highlights climate change as the dominant driver of future hydrological extremes in the UAB, emphasizing the need for climate-focused adaptation strategies to mitigate adverse impacts on water resources and livelihoods in the region.

本研究探讨了气候、土地利用和土地覆盖（LULC）变化对埃塞俄比亚上阿瓦什盆地（UAB）极端流量的预测影响。利用SSP4.5和SSP8.5条件下的高性能CMIP6气候模型，以及2030年代和2060年代在常规商业模式（BAU）和政府模式（GOV）下的未来LULC情景，采用SWAT模型模拟水文响应。结果表明：气候变化显著影响极端流量，具有高流量指数；最大高流量（MHF）、高流量脉冲数（HPC）、高流量脉冲持续时间（HPD）明显增加，低流量指标；最小低流量（MLF）、低流量脉冲数（LPC）和低流量脉冲持续时间（LPD）均大幅下降。例如，20世纪60年代SSP8.5条件下，MHF、HPC和HPD分别增加了63.16%、26.85%和14.96%，而MLF、LPC和LPD分别减少了67.11%、34.40%和5.95%。相比之下，在所有情景和时期，LULC变化对高流量和低流量指数的影响在统计上都不显著。BAU情景预测了大量的城市和农田扩张，导致森林和灌木面积减少，而GOV情景强调可持续土地管理，控制城市蔓延和增加森林覆盖。尽管存在这些差异，与气候变化的压倒性影响相比，lulc引起的极端流量变化仍然很小。本研究强调气候变化是UAB地区未来水文极端事件的主要驱动因素，强调需要以气候为重点的适应战略，以减轻对该地区水资源和生计的不利影响。

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引用次数: 0

Advancing global hindcast of extreme sea levels: Insights from a 65-year study 推进全球极端海平面的后估：来自65年研究的见解

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-19 DOI: 10.1016/j.wace.2025.100805

Pengcheng Wang , Natacha B. Bernier

Extreme sea levels (ESLs) are a leading cause of coastal hazards. Assessing risks and associated impacts requires reliable ESL statistics. These are typically derived from long but sparsely available tide-gauge records or through records obtained from long hindcasts. Here we present a 65-year global hindcast of hourly total sea levels that dynamically includes contributions from storm surges, tides, changes in water density (or baroclinicity) and their interactions. Evaluation shows good agreement between modelled and available observed sea levels, including extremes driven by extratropical and tropical cyclones. Significant improvements over other simulations result from our efforts in addressing underestimated reanalysis winds and incorporating baroclinicity, both of which have been overlooked in other global studies. The improvements can translate into reductions of return periods for given critical levels by decades. We therefore provide improved global estimates of ESL. In a first step toward developing seasonal forecast of flood risk, we also quantified ENSO-induced ESL modulations. The modulations show coherent spatial variabilities, consistent with ENSO-induced changes in the atmosphere and ocean. We also highlight the relevance of the often-overlooked neutral phase in regions where both El Niño and La Niña may suppress sea level variabilities.

极端海平面（esl）是沿海灾害的主要原因。评估风险和相关影响需要可靠的ESL统计数据。这些数据通常来自长期但很少得到的验潮记录，或来自长期后验的记录。在这里，我们提出了65年全球每小时总海平面的动态后报，其中包括风暴潮、潮汐、水密度变化（或斜压性）及其相互作用的贡献。评估结果表明，模拟的海平面与现有观测到的海平面，包括由温带和热带气旋驱动的极端海平面，有很好的一致性。与其他模拟相比，我们在解决被低估的再分析风和纳入斜压性方面的努力取得了重大进展，这两者在其他全球研究中都被忽视了。这些改进可以转化为将给定临界水平的回归期缩短数十年。因此，我们提供了改进的全球ESL估计。在开发洪水风险季节性预报的第一步，我们还量化了enso诱导的ESL调制。这些调制显示出连贯的空间变异性，与enso引起的大气和海洋变化一致。我们还强调了El Niño和La Niña可能抑制海平面变化的地区经常被忽视的中性阶段的相关性。

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引用次数: 0

Increased precipitation variability at multi-timescales in China since the 1960s 20世纪60年代以来中国多时间尺度降水变率的增加

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-18 DOI: 10.1016/j.wace.2025.100808

Xuyang Mo , Wenxia Zhang , Tianjun Zhou

The frequency and intensity of precipitation have changed significantly in China as previously reported. A relevant behavior is the variability of precipitation, which describes temporal fluctuations of precipitation events. Yet it remains unclear how precipitation variability has changed at different timescales over China. In this study, we show that precipitation variability has increased significantly since the 1960s, averaging 2.3 % per decade across China. The increase exists across the synoptic to intraseasonal timescales. The increase in precipitation variability is evident in all seasons with the greatest rate in winter in percentage, which is approximately three times as much as that in summer. Regionally, precipitation variability has risen significantly in northwestern, northeastern, and southeastern China, but has decreased insignificantly along the wet-dry transition belt extending from the north to southwestern China. Compared to trends in mean and extreme precipitation, the increase of precipitation variability is more widespread and with greater magnitudes. The changes in the top 10 % extreme precipitation events contribute ∼75 % of the amplification of precipitation variability nationwide. In addition to long-term trend, summer precipitation variability over eastern China is modulated by the Pacific Decadal Oscillation. This study revealed robust increases in precipitation variability over China since the 1960s across different timescales, seasons, and regions, which have far-reaching impacts on droughts, floods, and water resource management.

中国降水的频率和强度发生了显著变化。一个相关的行为是降水的变率，它描述了降水事件的时间波动。然而，目前尚不清楚中国不同时间尺度的降水变异性是如何变化的。在这项研究中，我们发现自20世纪60年代以来，中国的降水变率显著增加，平均每十年增加2.3%。这种增加在天气到季节内的时间尺度上都存在。各季节降水变率的增加都很明显，冬季的百分比增加幅度最大，约为夏季的3倍。从区域上看，中国西北部、东北部和东南部降水变率显著上升，而沿华北至西南的干湿过渡带降水变率下降不显著。与平均和极端降水趋势相比，降水变率的增加范围更广，幅度更大。前10%极端降水事件的变化贡献了全国降水变率放大的约75%。除了长期趋势外，中国东部夏季降水变率还受到太平洋年代际涛动的调制。研究表明，自20世纪60年代以来，中国不同时间尺度、季节和地区的降水变率显著增加，对干旱、洪水和水资源管理产生了深远的影响。

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引用次数: 0

The impact of aerosol forcing on the statistical attribution of heatwaves 气溶胶强迫对热浪统计归因的影响

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-12 DOI: 10.1016/j.wace.2025.100803

Florian Kraulich, Peter Pfleiderer, Sebastian Sippel

Heatwaves are becoming more frequent and intense due to anthropogenic climate change. Accurately attributing changes in their occurrence probability and intensity is crucial for effective climate change adaptation strategies. A common practice for calculating heatwave return periods in observations relies on extreme value statistics, where the Generalized Extreme Value distribution (GEV) shifts linearly with a covariate on global mean temperature (GMT) to capture the global forced response of climate change (‘standard method’, from now onwards). Although generally effective, this approach does not explicitly include regional aerosol trends, which strongly influence local heat extremes by reflecting solar radiation and altering cloud properties. Depending on the region, aerosol forcing trends can amplify or counteract greenhouse gas-induced warming. Here, we assess the impact of regional aerosol trends on statistical extreme event attribution of heatwaves using climate model simulations from the Community Earth System Model 2 (CESM2) large ensemble and single forcing large ensembles. To examine the impact of aerosols on extreme event trends, we introduce aerosol optical depth (AOD) as an additional covariate in the GEV model and compare this approach with the ‘standard method’. Our results show substantial biases of the ‘standard method’ in regions and periods of strong aerosol changes, particularly in industrial regions of North America, Central and Eastern Europe, and East Asia. Including AOD as a covariate significantly reduces these biases and improves return period estimates. This study highlights the importance of incorporating regional aerosol trends into statistical attribution frameworks to improve the estimation of return periods, and thus attribution statements.

由于人为气候变化，热浪正变得越来越频繁和强烈。准确地确定其发生概率和强度的变化对有效的气候变化适应战略至关重要。在观测中计算热浪重现期的一种常见做法依赖于极值统计，其中广义极值分布（GEV）随全球平均温度（GMT）的协变量线性移动，以捕获气候变化的全球强迫响应（“标准方法”，从现在开始）。虽然这种方法通常是有效的，但它没有明确地包括区域气溶胶趋势，而气溶胶趋势通过反射太阳辐射和改变云的性质而强烈地影响当地的极端高温。根据地区的不同，气溶胶强迫趋势可以放大或抵消温室气体引起的变暖。本文利用社区地球系统模式2 （CESM2）大集合和单一强迫大集合的气候模式模拟，评估了区域气溶胶趋势对热浪统计极端事件归因的影响。为了检验气溶胶对极端事件趋势的影响，我们在GEV模型中引入气溶胶光学深度（AOD）作为一个额外的协变量，并将这种方法与“标准方法”进行比较。我们的结果表明，在气溶胶变化强烈的地区和时期，特别是在北美、中欧和东欧以及东亚的工业区，“标准方法”存在很大的偏差。包括AOD作为协变量显著减少了这些偏差，并改善了回报期估计。这项研究强调了将区域气溶胶趋势纳入统计归因框架的重要性，以改进对回归期的估计，从而改进归因陈述。

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引用次数: 0

Drought attribution of climate drivers using machine learning techniques 使用机器学习技术的气候驱动因素的干旱归因

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-06 DOI: 10.1016/j.wace.2025.100801

Milton S. Speer, Lance M. Leslie

引用次数: 0

Changes in atmospheric circulation amplify extreme snowfall fueled by Arctic sea ice loss over high-latitude land 大气环流的变化放大了北极海冰在高纬度陆地上的消融所引发的极端降雪

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-05 DOI: 10.1016/j.wace.2025.100802

Yubo Liu , Qiuhong Tang , L. Ruby Leung , Deliang Chen , Jennifer A. Francis , Chi Zhang , Hans W. Chen , Steven C. Sherwood

Arctic sea-ice retreat has been linked to increased winter precipitation and heavy snowfall over land, likely due to a combination of enhanced evaporation from ice-free Arctic marginal seas (AMS) and changes in atmospheric circulation. However, their relative roles and contributions remain uncertain. Here, we show that a greater proportion of AMS evaporative moisture reached high-latitude land during the cold seasons from 1980–1989 to 2012–2021. Atmospheric circulation changes added an additional 13 % increase in the AMS moisture contribution, accounting for 11 % of the total increase in AMS-sourced land precipitation. Notably, 46 % of the increase in AMS-sourced extreme snowfall is attributed to circulation-driven landward moisture transport, representing an 84 % increase beyond the effect of enhanced AMS evaporation alone. Further analysis indicates that both the rise in Arctic moisture and the atmospheric circulation shifts are primarily driven by anthropogenic forcing. These findings highlight how atmospheric circulation changes amplify extreme snowfall fueled by AMS evaporation, underscoring the synergistic effects of Arctic sea ice loss and circulation change on high-latitude winter precipitation.

北极海冰的退缩与冬季降水的增加和陆地上的大雪有关，这可能是由于无冰的北极边缘海（AMS）的蒸发增强和大气环流变化的共同作用。然而，它们的相对作用和贡献仍然不确定。研究表明，在1980-1989年和2012-2021年的寒冷季节，AMS蒸发水分到达高纬度陆地的比例更大。大气环流变化使AMS水分贡献增加了13%，占AMS源陆地降水总增加量的11%。值得注意的是，由AMS引起的极端降雪增加的46%归因于环流驱动的向陆地输送水分，比AMS蒸发增强的影响增加了84%。进一步的分析表明，北极湿度的上升和大气环流的变化主要是由人为强迫驱动的。这些发现强调了大气环流变化如何放大由AMS蒸发引起的极端降雪，强调了北极海冰损失和环流变化对高纬度冬季降水的协同效应。

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引用次数: 0

Discernability of the vertical vortex structure of pre-existing disturbances and their implication for tropical cyclone formation 已存在扰动的垂直涡旋结构的可分辨性及其对热带气旋形成的意义

IF 6.9 1区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Weather and Climate Extremes

Pub Date : 2025-09-05 DOI: 10.1016/j.wace.2025.100804

Hung Ming Cheung , Jung-Eun Chu

The formation of a tropical cyclone (TC) is often rooted in a pre-existing disturbance, yet our understanding of their structural differences and evolution into TCs remains limited. To bridge the knowledge gap, we examine tropical disturbances and depressions in the western North Pacific during the period 2004–2021 from a best-track dataset. Here we show four discernible structures of pre-existing disturbances in terms of their vertical and radial extents: broad vortex dominated by lower-tropospheric vorticity (Cluster 1), narrow vortex with its vorticity maximum in the lower troposphere (Cluster 2), broad and deep vortex spanning most of the troposphere (Cluster 3), and narrow vortex dominated by upper-tropospheric vorticity (Cluster 4), by applying unsupervised machine learning techniques. Out of the 2014 samples analyzed, almost 80 % exhibit vorticity maximum in the lower troposphere, while the others peak aloft. While these different structures have varying implications for stratiform and convective precipitations, there is no clear preference for specific vortex structures in pre-existing disturbances for TC genesis in the next 6 h. On the other hand, the time it takes for TC genesis or the intensification rate is more closely related to the upper-level extent of relative vorticity rather than the local maximum magnitude or radial size of the vortices. Despite the uncertainty concerning the data during the earlier lifetime, the study introduces a systematic approach to categorizing the vortex structures of pre-existing disturbances which provides new insights into their role in TC formation.

热带气旋（TC）的形成通常植根于预先存在的扰动，但我们对它们的结构差异和向TC演变的理解仍然有限。为了弥补知识差距，我们从最佳跟踪数据集中研究了2004-2021年期间北太平洋西部的热带扰动和低气压。通过应用无监督机器学习技术，我们展示了四种可识别的已存在扰动结构：由对流层低层涡度主导的宽涡（簇1），涡度最大的对流层低层涡（簇2），跨越大部分对流层的宽深涡（簇3），以及由对流层上层涡度主导的窄涡（簇4）。在分析的2014个样本中，几乎80%的涡度在对流层下层达到最大值，而其他的则在高空达到峰值。虽然这些不同的结构对层状降水和对流降水有不同的影响，但在接下来的6小时内，对已有扰动中的特定涡结构的TC形成没有明显的偏好。另一方面，TC形成所需的时间或增强速率与上层相对涡度的程度更密切相关，而不是与当地最大涡的大小或径向大小密切相关。尽管早期的数据存在不确定性，但该研究引入了一种系统的方法来对预先存在的扰动的涡结构进行分类，这为它们在TC形成中的作用提供了新的见解。

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引用次数: 0