Rossby Wave

Rossby (planetary) waves owe their existence to the variation of the Coriolis parameter with latitude (the beta-effect) and conserve potential vorticity. In the ocean they are long, slow, westward-propagating waves that adjust the interior to changed wind forcing over months to years and set the timescale of basin-scale circulation. Atmospheric Rossby waves are the meandering mid-latitude jet-stream troughs and ridges that steer weather systems.