= Atmospheric super-rotation
{wiki}
= Atmospheric superrotation
{synonym}
<Atmospheric superrotation> is circulation whose axial <angular momentum> per unit <mass> exceeds that of the underlying body's equator. An eastward equatorial jet is a common manifestation, but it requires a continuing source of equatorial momentum convergence rather than merely a local temperature difference.
In models of <exoplanets> under <tidal locking>, day-night heating excites large-scale <Rossby waves> and <Kelvin waves>. Their phase structure transports eastward momentum toward the equator and can maintain the jet against drag. This mechanism was demonstrated using an analytic model and numerical calculations of increasing complexity.<Equatorial superrotation on tidally locked exoplanets by Adam P. Showman and Lorenzo M. Polvani>[Abstract: standing Rossby/Kelvin waves, phase tilts and equatorial momentum convergence]{ref} Such a jet can shift a bright atmospheric region eastward, affecting an <exoplanet thermal phase curve>, although a brightness offset alone does not uniquely measure a wind speed.
Back to article page
