From Random Walks to Thermal Rides: Universal Anomalous Transport in Soaring Flights

TL;DR

This study reveals a universal anomalous transport law in soaring flights, showing persistent sub-ballistic horizontal motion driven by atmospheric intermittency, with implications for understanding transport in natural and physical systems.

Contribution

It uncovers a universal scaling law for soaring flight trajectories and links it to atmospheric intermittency and persistent correlations, advancing understanding of transport phenomena in natural systems.

Findings

Horizontal motion is persistently sub-ballistic with a Hurst exponent ~0.88.

Intermittent, two-dimensional, and correlated nature of soaring transport causes scaling.

Learning improves exploration during the search phase, aiding thermal detection.

Abstract

Cross-country soaring flights rely on intermittent atmospheric updrafts to cover long distances, producing trajectories that alternate between rapid relocation and local exploration. From a large dataset of paraglider, hang glider, and sailplane flights, we uncover a universal transport law: beyond short ballistic times, horizontal motion is persistently sub-ballistic, with a Hurst exponent $\approx 0.88$ largely independent of aircraft type. Phase-resolved analysis using a probabilistic segmentation method shows that this scaling arises from the fundamentally intermittent, two-dimensional, and directionally correlated nature of soaring transport, in which successive ballistic segments do not add coherently. We find that learning, in the sense of experience-driven improvements in exploration and decision-making, manifests primarily in the search phase, enhancing the ability to efficiently probe the air mass and locate the next thermal. Overall, our results suggest that atmospheric structure and the generic organization of the transition-search-climb cycle dominate transport properties, placing human soaring alongside biological and physical systems where anomalous transport emerges from intermittency and persistence.