Automatic Analysis of Trough Lines Based on Curvature Tracing

Abstract

To solve the problems that arise in traditional automatic methods for trough line analysis with regard to low processing efficiency and analytical accuracy, an automatic method for trough line analysis was proposed in this study, comprising the following steps. Firstly, the curvature of contour lines was calculated using geopotential height field data to extract tracing start points, and candidate and non-candidate trough points were classified and recognized based on their curvature and relative positions. Afterwards, among the candidates, the eligible trough points were connected from tracing start point. Finally, the automatically analyzed trough lines were obtained after some post-processing steps. The experimental results indicate that the method is able to effectively identify meteorological trough lines, and that its performance is superior to some previous analysis methods of trough line in terms of analytical accuracy and processing speed.

Seamless Detection of Cutoff Lows and Preexisting Troughs

“…Some heightbased schemes have detected the troughs or frontal structures as axes (Knippertz 2004;Bueh and Xie 2015). Li et al (2018) and Schemm et al (2020) used the curvature of the geopotential height to detect troughs and ridges. Some trough detection schemes obtain the tilts of the axis (e.g., Bueh and Xie 2015;Schemm et al 2020), which are essential for trough life cycles up to wave-breaking events (Thorncroft et al 1993).…”