In the article “Poleward expansion of tropical cyclone latitudes in warming climates”, published in the New Year's issue of Nature Geoscience, the authors Joshua Studholme, Alexey V. Fedorov, Sergey K. Gulev, Kerry Emanuel and Kevin Hodges analyze the dynamics of tropical cyclones over the past few million years.

Tropical cyclones generally form at low latitudes with access to the warm waters of the tropical oceans, but far enough off the equator to allow planetary rotation to cause aggregating convection to spin up into coherent vortices. Yet, current prognostic frameworks for TC latitudes make contradictory predictions for climate change.

Simulations of past warm climates, such as the Eocene and Pliocene, show that TCs can form and intensify at higher latitudes than of those during pre-industrial conditions. Observations and model projections for the twenty-first century indicate that TCs may again migrate poleward in response to anthropogenic greenhouse gas emissions, which poses profound risks to the planet’s most populous regions.

Previous studies largely neglected the complex processes that occur at temporal and spatial scales of individual storms as these are poorly resolved in numerical models. Here we review this mesoscale physics in the context of responses to climate warming of the Hadley circulation, jet streams and Intertropical Convergence Zone. We conclude that twenty-first century TCs will most probably occupy a broader range of latitudes.

Studholme, J., Fedorov, A.V., Gulev, S.K. et al. Poleward expansion of tropical cyclone latitudes in warming climates. Nat. Geosci. (2021). DOI:10.1038/s41561-021-00859-1