Picture (above): Hurricane pictured from space. Credit: Pixabay/Pexels.

Tropical cyclones form under certain atmospheric conditions within different large‐scale disturbances across various ocean basins. Every year a large number of tropical disturbances form across global ocean basins, but only a few of them develop into tropical cyclones, with a geographical variation in the number of formations.

Previous studies on the differences in the environmental conditions of developing versus non-developing tropical disturbances focus on the Atlantic and Pacific Ocean basins due to fewer observations in other ocean basins. The recent development of the “marsupial pouch” theory of tropical cyclone formation has led to the development of a detection scheme to identify the locations within large‐scale disturbances that have the potential for tropical cyclone formation.

The detection scheme was tuned to detect the initial tropical depressions in addition to developed tropical storms. This scheme helped the researchers to investigate the environmental differences between developing and non-developing tropical depressions in all ocean basins. The environmental variables inhibiting tropical storm formation differ among ocean basins, with structural differences from the lower to upper troposphere disrupting sustained convection in non-developing cases.

The study identifies the potential limiting factors for tropical storm formation across different ocean basins.

  • Paper: Raavi, P.H., and K.J.E. Walsh, 2020: Basinwise statistical analysis of factors limiting tropical storm formation from an initial tropical circulation. Journal of Geophysical Research (Atmospheres), 125, e2019JD032006, doi: 10.1029/2019JD032006.