The role of diabatic heating in Rossby wave breaking

Rossby wave breaking (RWB) is a key process through which synoptic-scale eddies reorganize the extratropical circulation, interacting with jet shifts, storm track variability, and the persistence of weather regimes. Despite extensive evidence that diabatic heating strongly influences synoptic eddies and supports blocking, its influence on when and how Rossby waves break remains largely unexplored. This gap limits our physical understanding of how moist processes reshape the potential vorticity structure that governs RWB and, in turn, the large-scale circulation.

We investigate the influence of diabatic processes on RWB using aquaplanet simulations at 100, 20, and 2.5 km horizontal resolution, which systematically alter the representation of diabatic heating. By comparing RWB frequency, geometry, and life cycles across resolutions, we isolate how the resolution-dependent representation of diabatic heating shapes RWB and the RWB-mediated circulation response, including jet latitude and storm track position. These idealized results are complemented by an observational analysis of RWB events and associated warm conveyor belts in ERA5 reanalyses.

Together, these analyses provide new physical insight into how diabatic processes modulate RWB and thereby shape the extratropical circulation, with implications for the interpretation of resolution-dependent circulation biases and the representation of moist processes in weather and climate models.