Atmospheric blocking events are quasi-stationary high-pressure systems that disrupt the typical paths of polar and subtropical air currents, often producing prolonged extreme weather events such as summer heat waves or winter cold spells. Despite their critical role in shaping mid-latitude weather, accurately modeling and analyzing blocking events in long meteorological records remains a significant challenge. To address this challenge, we present an uncertainty visualization framework for detecting and characterizing atmospheric blocking events. First, we introduce a geometry-based detection and tracking method, evaluated on both pre-industrial climate model simulations (UKESM) and reanalysis data (ERA5), which represent historical Earth observations assimilated from satellite and station measurements onto regular numerical grids using weather models. Second, we propose a suite of uncertainty-aware summaries: contour boxplots that capture representative boundaries and their variability, frequency heatmaps that encode occurrences, and 3D temporal stacks that situate these patterns in time. Third, we demonstrate our framework in a case study of the 2003 European heatwave, mapping the spatiotemporal occurrences of blocking events using these summaries. Collectively, these uncertainty visualizations reveal where blocking events are most likely to occur and how their spatial footprints evolve over time. We envision our framework as a valuable tool for climate scientists and meteorologists: by analyzing how blocking frequency, duration, and intensity vary across regions and climate scenarios, it supports both the study of historical blocking events and the assessment of scenario-dependent climate risks associated with changes in extreme weather linked to blocking.

翻译：大气阻塞事件是准静止的高压系统，它们扰乱了极地与副热带气流的典型路径，常导致夏季热浪或冬季寒潮等持续性极端天气事件。尽管阻塞事件对中纬度天气的形成具有关键作用，但在长期气象记录中准确建模与分析阻塞事件仍是一项重大挑战。为应对这一挑战，我们提出了一个用于检测和表征大气阻塞事件的不确定性可视化框架。首先，我们提出了一种基于几何的检测与追踪方法，该方法在工业革命前气候模型模拟（UKESM）和再分析数据（ERA5）上进行了评估——这些数据代表了通过天气模型将卫星与站点观测资料同化到规则数值网格上的历史地球观测。其次，我们提出了一套不确定性感知的摘要工具：捕捉代表性边界及其变异性的轮廓箱线图、编码发生频率的热力图，以及将这些模式置于时间维度中的三维时间堆叠图。第三，我们以2003年欧洲热浪为例展示了该框架，利用这些摘要工具绘制了阻塞事件的时空发生图谱。总体而言，这些不确定性可视化揭示了阻塞事件最可能发生的区域及其空间足迹随时间演变的过程。我们设想该框架将成为气候科学家和气象学家的宝贵工具：通过分析阻塞事件的频率、持续时间和强度在不同区域及气候情景下的变化，它既支持对历史阻塞事件的研究，也有助于评估与阻塞相关的极端天气变化所对应的情景依赖性气候风险。