Study of Interaction and Complete Merging of Binary Cyclones Using Complex Networks

TL;DR

This paper introduces a network-based method to analyze and predict the complete merging of binary cyclones by tracking their interactions through evolving velocity networks, offering better early warning indicators.

Contribution

It presents a novel application of complex network analysis to cyclone interactions, providing new indicators for classifying interaction stages and predicting mergers.

Findings

Network indicators outperform separation distance in classifying interaction stages.

In-degree and out-degree quantify the evolution of cyclone interactions.

Network measures can predict cyclone mergers before they occur.

Abstract

Cyclones are amongst the most hazardous extreme weather events on Earth. When two co-rotating cyclones come in close proximity, a possibility of complete merger (CM) arises due to their interactions. However, identifying the transitions in the interaction of binary cyclones and predicting the merger is challenging for weather forecasters. In the present study, we suggest an innovative approach to understand the evolving vortical interactions between the cyclones during two such CM events using time-evolving induced velocity based unweighted directed networks. We find that network-based indicators, namely, in-degree and out-degree, can quantify the changes during the interaction between two cyclones and are better candidates than the traditionally used separation distance to classify the interaction stages before a CM. The network indicators also help to identify the dominating cyclone during the period of interaction and quantify the variation of the strength of the dominating and merged cyclones. Finally, we show that the network measures also provide an early indication of the CM event well before its occurrence.