Rossby Waves and Implications in Weather and Space Weather

Dear Colleagues,

Rossby waves are a class of inertial waves, occurring in thin layers within fluid regions of stars and planets due to the variation in Coriolis forces with latitude. The discovery of Rossby waves (Rossby, 1939) in the Earth's atmosphere led to great advances in the ability to forecast our planet's weather patterns. It is the combination of mean west-to-east atmospheric flow and (finite amplitude) Rossby waves in the atmosphere that creates “jet streams” at midlatitudes. Understanding their interactions and the resulting longitudinal structure allows for an accurate prediction of how synoptic weather patterns evolve and propagate to the east. In effect, the “jet stream” steers our Earth's weather from location to location in midlatitudes. Over the past several years, observational evidence has indicated that there are also Rossby waves in the Sun. Although Rossby waves are detected in the Sun's photosphere and corona, they most likely originate in layers where the vertical extent and radial motions are much less than the horizontal extent and motions. Solar tachocline is such a layer where Rossby waves can be generated in the Sun, and because of predominantly horizontal motions of supergranules in the sub-photospheric layer, this layer can also be a generation layer for solar Rossby waves. Rossby waves differ from their Earth counterparts by being strongly modified by the magnetic fields in the Sun. After discussing the basics of solar Rossby waves, we will present a few recent simulations of nonlinear interactions between Rossby waves and magnetic fields in solar tachocline. We will show that “tachocline nonlinear oscillations” (TNOs) occur, very much like nonlinear Orr mechanism in fluid dynamics. TNOs have periods similar to those observed in the solar atmosphere—enhanced periods of solar activity, or “seasons”—occurring at intervals between six months and two years. These seasonal/subseasonal activity bursts produce the strongest eruptive space weather events. Thus, a key to forecasting the timing, amplitude, and location of future activity bursts, and hence space weather events, could lie in our ability to simulate the longitudinal patterns produced by the interactions of Rossby waves and magnetic fields.

Dr. Mausumi Dikpati
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Atmosphere is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.