Visualization of Idealized Atmospheric-River-like Features

<p>In an idealized&nbsp;simulation of a shallow-water fluid,&nbsp;all the poleward transport of a water vapor-like tracer transport is produced by AR-like filamentary structures.&nbsp;&nbsp;This dry simulation is initialized with a barotropically unstable midlatitude jet stream and a passive tracer in the tropics. Due to the idealized nature of the simulation, we can unequivocally identify the formation of a Rossby wave in the jet stream. &nbsp;In the tracer field, this wave leads to turbulent stirring and generates long, narrow filamentary structures that have a similar aspect ratio as ARs. &nbsp;Based on our experiment setup, these structures should be responsible for all the meridional tracer transport in the extratropics.&nbsp;</p>