The Prospects for Hurricane-like Vortices in Protoplanetary Disks

TL;DR

This paper explores whether water sublimation energy can sustain or amplify anticyclonic vortices in protoplanetary disks, potentially aiding planetesimal formation, by analyzing analogies with tropical cyclones and supporting simulations.

Contribution

It introduces a novel mechanism where sublimation energy extends vortex lifetimes in protoplanetary disks, enhancing particle trapping and planetesimal formation prospects.

Findings

Sublimation energy can prolong vortex lifetimes in disks.

Vortices near the water ice line are most affected.

Mechanism may facilitate planetesimal formation.

Abstract

When ice on the surface of dust grains in protoplanetary disk sublimates, it adds its latent heat of water sublimation to the surrounding flow. Drawing on the analogy provided by tropical cyclones on Earth, we investigate if this energy source is sufficient to sustain or magnify anticyclonic disk vortices that would otherwise fall victim to viscous dissipation. An analytical treatment, supported by exploratory two-dimensional simulations, suggests that even modestly under-saturated flows can extend the lifetime of vortices, potentially to a degree sufficient to aid particle trapping and planetesimal formation. We expect the best conditions for this mechanism to occur will be found near the disk's water ice line if turbulent motions displace gas parcels out of thermodynamic equilibrium with the dust mid-plane.