Global warming strengthens atmospheric ducting

Atmospheric ducts (ADs) provide efficient electromagnetic wave channels for beyond line-of-sight (BLOS) propagation and can serve as a sensitive diagnostic factor for the change of lower atmosphere. Based on the ERA5 model-level reanalysis data (1979–2024), a global-scale assessment of the response of AD evolution to global warming has been revealed for the first time. The occurrence probability, strength, and top height of AD all exhibit an increasing trend over mid- to low-latitude oceans. Analysis of underlying physical mechanisms indicates that this long-term trend is highly coupled with the continuous increase in atmospheric static stability within the lower marine atmosphere in the context of global warming. While interannual variability—typified by the El Niño–Southern Oscillation—modulates the amplitude of these anomalies, the long-term trajectory is overwhelmingly dictated by the secular trend. Ultimately, continuous warming is shifting the marine atmospheric background state toward a regime favoring more frequent and intense ducting, with profound implications for maritime BLOS communication and radar detection.