Exploring Cyclone Evolution with Hierarchical Features

Emma Nilsson, Jonas Lukasczyk, Wito Engelke, Talha Bin Masood, Gunilla Svensson, Rodrigo Caballero, Christoph Garth, Ingrid Hotz

View presentation:2022-10-17T21:34:00ZGMT-0600Change your timezone on the schedule page
2022-10-17T21:34:00Z
Exemplar figure, described by caption below
The image shows the results of tracking the extratropical cyclone Klaus using our framework for cyclone tracking and exploration with hierarchical features. On the left is a nested tracking graph, where the hierarchical features used are the proposed crown components, showing two parameter settings at once. The tracks are colored by cyclone and linked to the spatial view of the globe, see the right image. We capture the split-merge event for Klaus over the Mediterranean on January 24th, 2009, but the graph shows that detection would have been impossible for a higher hierarchy level, see upper left.

The live footage of the talk, including the Q&A, can be viewed on the session page, TopoInVis: Session 2, Early Career Lightning Talks + Best Paper Awards .

Keywords

Human-centered computing—Visualization—Visualization design and evaluation methods; Human-centered computing—Visualization—Visualization application domains—Scientific visualization

Abstract

The problem of tracking and visualizing cyclones is still an active area of climate research, since the nature of cyclones varies depending on geospatial location and temporal season, resulting in no clear mathematical definition. Thus, many cyclone tracking methods are tailored to specific datasets and therefore do not support general cyclone extraction across the globe. To address this challenge, we present a conceptual application for exploring cyclone evolution by organizing the extracted cyclone tracks into hierarchical groups. Our approach is based on extrema tracking, and the resulting tracks can be defined in a multi-scale structure by grouping the points based on a novel feature descriptor defined on the merge tree, so-called crown features. Consequently, multiple parameter settings can be visualized and explored in a level-of-detail approach, supporting experts to quickly gain insights on cyclonic formation and evolution. We describe a general cyclone exploration pipeline that consists of four modular building blocks: (1) an extrema tracking method, (2) multiple definitions of cyclones as groups of extrema, including crown features, (3) the correlation of cyclones based on the underlying tracking information, and (4) a hierarchical visualization of the resulting feature tracks and their spatial embedding, allowing exploration on a global and local scale. In order to be as flexible as possible, our pipeline allows for exchanging every module with different techniques, such as other tracking methods and cyclone definitions.