I will discuss the mechanisms of zonal jets, and in particular of equatorial superrotation, using very idealized numerical models using the primitive equations on the sphere. It is well known that zonal jets robustly arise in rotating atmospheres there is a wavemaker at a particular latitude. Rossby waves are then generated that propagate away, and eastward momentum converging on the source region producing a zonal jet. Such a mechanism produces the jet stream on Earth and, most likely, the jets on giant planets including the equatorial superrotation. However, on slowly rotating terrestrial atmospheres it seems unlikely that superrotation is produced by that mechanism. Rather, simulations indicate that, at small thermal Rossby number, a mechanism involving equatorial Kelvin waves is involved.
The seminar will be webcast and recorded for future viewing. The live URL for the webcast is http://www.fin.ucar.edu/it/mms/fl-live.htm The recording will be linked at the web site for the Thompson Lecture Series (link below).