# The hottest hot Jupiters may host Atmospheric Dynamos

## TL;DR

This paper demonstrates through simulations and analysis that hot Jupiters can sustain atmospheric dynamos driven by asymmetric stellar heating, leading to stronger surface magnetic fields and altered magnetic geometries.

## Contribution

It introduces the concept of an atmospheric dynamo in hot Jupiters, independent of deep-seated dynamos, driven by conductivity variations from stellar heating.

## Key findings

- Atmospheric dynamos can be maintained in hot Jupiters' atmospheres.
- Surface magnetic fields are significantly increased by atmospheric dynamos.
- Magnetic field geometry is altered, affecting star-planet interactions.

## Abstract

Hot Jupiters have proven themselves to be a rich class of exoplanets which test our theories of planetary evolution and atmospheric dynamics under extreme conditions. Here, we present three-dimensional magnetohydrodynamic simulations and analytic results which demonstrate that a dynamo can be maintained in the thin, stably-stratified atmosphere of a hot Jupiter, independent of the presumed deep-seated dynamo. This dynamo is maintained by conductivity variations arising from strong asymmetric heating from the planets' host star. The presence of a dynamo significantly increases the surface magnetic field strength and alters the overall planetary magnetic field geometry, possibly affecting star-planet magnetic interactions.