The surface of a body massive enough to take a spherical shape can be defined by pressure if it is a gas giant. Whatever material the surface mantle of Jupiter consists of must be a compound that exists as liquid(at least) at the pressure it is under. This pressure boundary should also exclude the materials that make up Jupiter’s atmosphere, defining a zone of exclusion between the atmosphere and the surface.
Due to the velocity disparities present between the atmosphere, surface and core structure, this surface/atmosphere exclusion zone should also maintain a high electromagnetic resistance. It would be through this resistance I would assume that drag between the atmosphere and the surface is facilitated.
As the degree of drag between the surface and atmosphere is this pronounced it should subsequently follow that a zero medium occur. This hypothesis provides a connection between gas giant vortexes and solar flaring as related phenomena.