Evidence of Rossby Waves in the Sun

Rossby waves are a well-documented phenomenon in the Earth's atmosphere, the Jet Stream being one prominent example. These giant meanders are caused by the Coriolis effect, due to the rotation of the planet, as well as being a result of the shearing between different layers of the atmosphere. While the sun has never been conclusively shown to have Rossby waves, because the sun is also a rotating mass of different layers of fluid and gas, one might suspect they are also apparent in the solar atmosphere.

Through analysis of bright point (~3-5 Mm regions of high EUV and X-ray activity on the sun) statistics using data from Stereo A and B, as well as AIA, an analysis was done to determine if these large-scale wave-like patterns could be found in the solar atmosphere. Through the compilation of a number of years worth of data, clear motion of the bright points in a quasi-sinusoidal pattern, closely resembling Rossby Wave Trains (RWT's) was detected.

Because the migration of bright points from the poles towards the equator of the sun has been shown to be closely related to the sun spot cycle, understanding how Rossby waves are related to this movement is essential to understanding the nature of the solar cycle. Furthermore, while research is still in the preliminary stages, we suspect g-nodes (larger zones of magnetic activity, ~150-250 Mm in size) will also move in these Rossby wave type patterns. G-node's evolution and movement also appears to be related to solar flare prediction. Thus, the discovery of these Rossby waves on the sun could have important implications for further advances in the prediction of space weather events.